Crystalline forms of (s)-2-ethylbutyl 2-(((s)-(((2r,3s,4r,5r)-5- (4-aminopyrrolo[2,1-f] [1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy) (phenoxy) phosphoryl)amino)propanoate

ABSTRACT

The present invention relates to novel salts and crystalline forms of (S)-2-ethylbutyl 2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate for use in treating viral infections. In some embodiments, the viral infection is caused by a virus selected from the group consisting of Arenaviridae, Coronaviridae, Filoviridae, Flaviviridae, and Paramyxoviridae.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/492,364, filed May 1, 2017, which is incorporated herein in itsentirety for all purposes.

FIELD

The present invention relates to novel crystalline forms of(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate,the pharmaceutical formulations, and the therapeutic uses thereof intreating viral infections.

BACKGROUND OF THE INVENTION

Prevention and treatment methods for some Arenaviridae, Coronaviridae,Filoviridae, Flaviviridae, and Paramyxoviridae viruses presentchallenges due to a lack of vaccine or post-exposure treatment modalityfor preventing or managing these infections. In some cases, patientsonly receive supportive and resource intensive therapy such aselectrolyte and fluid balancing, oxygen, blood pressure maintenance, ortreatment for secondary infections. Thus, there is a need for antiviraltherapies having a potential for broad antiviral activity.

The compound (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate, referred herein as Compound 1 or Formula I,is known to exhibit antiviral properties against Arenaviridae,Coronaviridae, Filoviridae, and Paramyxoviridae viruses as described inWarren, T. et al., Nature (2016) 531:381-385 and antiviral activitiesagainst Flaviviridae viruses as described in co-pending U.S. provisionalpatent application No. 62/325,419 filed Apr. 20, 2016.

(S)-2-Ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate or 2-ethylbutyl((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate,(Formula I), has the following structure:

It is desired to have physically stable forms of the compound that aresuitable for the therapeutic use and the manufacturing process.

BRIEF SUMMARY OF THE INVENTION

In some embodiments, the present invention is directed to novel forms ofFormula I.

In some embodiments, the present invention is directed to crystallineforms of (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate.

In some embodiments, the present invention is directed to(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm I (Formula I Form I).

In some embodiments, the present invention is directed to(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm II (Formula I Form II).

In some embodiments, the present invention is directed to(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm III (Formula I Form III).

In some embodiments, the present invention is directed to(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm IV (Formula I Form IV)

In some embodiments, the present invention is directed to a mixture of(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatecrystalline forms (Formula I Mixture).

In some embodiments, the present invention is directed to a mixture of(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm II and (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm IV (Mixture of Formula I Form II and Formula I Form IV).

In some embodiments, the present invention is directed to a mixture ofcrystalline forms of (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(Mixture I)

In some embodiments, the present invention is directed to a mixture ofcrystalline forms of (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(Mixture II)

In some embodiments, the present invention is directed to a mixture ofcrystalline forms of (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(Mixture III)

In some embodiments, the present invention is directed to(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatemaleate Form I (Formula I Maleate Form I)

In some embodiments, the present invention is directed to methods oftreating an Arenaviridae, Coronaviridae, Filoviridae, Flaviviridae, orParamyxoviridae virus infection by administering a compound of Formula Iprovided herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: XRPD pattern for Formula I Form I.

FIG. 2: DSC for Formula I Form I.

FIG. 3: TGA for Formula I Form I.

FIG. 4: DVS for Formula I Form I.

FIG. 5: XRPD pattern for Formula I Form II.

FIG. 6: DSC for Formula I Form II.

FIG. 7: TGA for Formula I Form II.

FIG. 8: DVS for Formula I Form II.

FIG. 9: Calculated XRPD pattern for Formula I Form III.

FIG. 10: XRPD pattern for Form Formula I IV.

FIG. 11: DSC for Formula I Form IV.

FIG. 12: TGA for Formula I Form IV.

FIG. 13: XRPD pattern for a mixture of Formula I Form II and Formula IForm IV of Formula I (Mixture I).

FIG. 14: DSC for a mixture of Formula I Form II and Formula I Form IV ofFormula I (Mixture I).

FIG. 15: TGA for a mixture of Formula I Form II and Formula I Form IV ofFormula I (Mixture I).

FIG. 16: XRPD pattern for a mixture of Formula I Form II and Formula IForm IV of Formula I (Mixture II).

FIG. 17: DSC for a mixture of Formula I Form II and Formula I Form IV ofFormula I (Mixture II).

FIG. 18: TGA for a mixture of Formula I Form II and Formula I Form IV ofFormula I (Mixture II).

FIG. 19: XRPD pattern for a mixture of Formula I Form II and Formula IForm IV of Formula I (Mixture III).

FIG. 20: DSC for a mixture of Formula I Form II and Formula I Form IV ofFormula I (Mixture III).

FIG. 21: TGA for a mixture of Formula I Form II and Formula I Form IV ofFormula I (Mixture III).

FIG. 22: XRPD pattern Formula I Maleate Form I.

FIG. 23: DSC for Formula I Maleate Form I.

FIG. 24: TGA for Formula I Maleate Form I.

FIG. 25: DVS for Formula I Maleate Form I.

FIG. 26: XRPD pattern for Formula I Form IV.

FIG. 27: Solid state NMR for Formula I Form II.

FIG. 28: Solid state NMR for a mixture of Formula I Form II and Form IV(top), Mixture III (middle) and Mixture I (bottom).

FIG. 29: Solid state NMR for Mixture III (top), a mixture of Formula IForm II and Form IV (middle), and Mixture II (bottom).

DETAILED DESCRIPTION OF THE INVENTION I. General

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various embodiments of theinvention. However, one skilled in the art will understand that theinvention may be practiced without these details. The description belowof several embodiments is made with the understanding that the presentdisclosure is to be considered as an exemplification of the claimedsubject matter, and is not intended to limit the appended claims to thespecific embodiments illustrated. The headings used throughout thisdisclosure are provided for convenience only and are not to be construedto limit the claims in any way. Embodiments illustrated under anyheading may be combined with embodiments illustrated under any otherheading.

II. Definitions

Unless the context requires otherwise, throughout the presentspecification and claims, the word “comprise” and variations thereof,such as, “comprises” and “comprising” are to be construed in an open,inclusive sense, that is as “including, but not limited to”.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the present invention. Thus, the appearances of thephrases “in one embodiment” or “in an embodiment” in various placesthroughout this specification are not necessarily all referring to thesame embodiment. Furthermore, the particular features, structures, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Embodiments that reference throughout this specification to “a Compoundof Formula I” includes the crystalline, salt, co-crystal, and solvateforms of the formulas and/or compounds disclosed herein. Thus, theappearance or the phrase “a Compound of Formula I” comprises crystallineForms I-IV and mixtures of crystalline forms thereof, Mixtures I-III,and Formula I Maleate Form I.

The invention disclosed herein is also meant to encompass allpharmaceutically acceptable compounds of Formula I beingisotopically-labeled by having one or more atoms replaced by an atomhaving a different atomic mass or mass number. Examples of isotopes thatcan be incorporated into the disclosed compounds include isotopes ofhydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine, chlorine, andiodine, such as ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹³N, ¹⁵N, ¹⁵O, ¹⁷O, ¹⁸O, ³¹P,³²P, ³⁵S, ¹⁸F, ³⁶Cl, ¹²³I, and ¹²⁵I, respectively. These radiolabeledcompounds could be useful to help determine or measure the effectivenessof the compounds, by characterizing, for example, the site or mode ofaction, or binding affinity to pharmacologically important site ofaction. Certain isotopically-labeled compounds of Formula I, forexample, those incorporating a radioactive isotope, are useful in drugand/or substrate tissue distribution studies. The radioactive isotopestritium, i.e. ³H, and carbon-14, i.e. ¹⁴C, are particularly useful forthis purpose in view of their ease of incorporation and ready means ofdetection.

Substitution with heavier isotopes such as deuterium, i.e. ²H, mayafford certain therapeutic advantages resulting from greater metabolicstability. For example, in vivo half-life may increase or dosagerequirements may be reduced. Thus, heavier isotopes may be preferred insome circumstances.

Substitution with positron emitting isotopes, such as ¹¹C, ¹⁸F, ¹⁵O and¹³N, a N, can be useful in Positron Emission Topography (PET) studiesfor examining substrate receptor occupancy. Isotopically-labeledcompounds of Formula I can generally be prepared by conventionaltechniques known to those skilled in the art or by processes analogousto those described in the Examples as set out below using an appropriateisotopically-labeled reagent in place of the non-labeled reagentpreviously employed.

“Stable compound” and “stable structure” are meant to indicate acompound that is sufficiently robust to survive isolation to a usefuldegree of purity from a reaction mixture, and formulation into anefficacious therapeutic agent.

“Optional” or “optionally” means that the subsequently described eventor circumstances may or may not occur, and that the description includesinstances where said event or circumstance occurs and instances in whichit does not. For example, “optionally substituted aryl” means that thearyl radical may or may not be substituted and that the descriptionincludes both substituted aryl radicals and aryl radicals having nosubstitution.

“Pharmaceutically acceptable excipient” includes without limitation anyadjuvant, carrier, excipient, glidant, sweetening agent, diluent,preservative, dye/colorant, flavor enhancer, surfactant, wetting agent,dispersing agent, suspending agent, stabilizer, isotonic agent, solvent,or emulsifier which has been approved by the United States Food and DrugAdministration as being acceptable for use in humans or domesticanimals.

A “pharmaceutical composition” refers to a formulation of a compound ofthe invention and a medium generally accepted in the art for thedelivery of the biologically active compound to mammals, e.g., humans.Such a medium includes all pharmaceutically acceptable excipientstherefor.

“Effective amount” or “therapeutically effective amount” refers to anamount of a compound according to the invention, which when administeredto a patient in need thereof, is sufficient to effect treatment fordisease-states, conditions, or disorders for which the compounds haveutility. Such an amount would be sufficient to elicit the biological ormedical response of a tissue system, or patient that is sought by aresearcher or clinician. The amount of a compound according to theinvention which constitutes a therapeutically effective amount will varydepending on such factors as the compound and its biological activity,the composition used for administration, the time of administration, theroute of administration, the rate of excretion of the compound, theduration of the treatment, the type of disease-state or disorder beingtreated and its severity, drugs used in combination with orcoincidentally with the compounds of the invention, and the age, bodyweight, general health, sex and diet of the patient. Such atherapeutically effective amount can be determined routinely by one ofordinary skill in the art having regard to their own knowledge, thestate of the art, and this disclosure.

The term “treating”, as used herein, unless otherwise indicated, meansreversing, alleviating, inhibiting the progress of, or preventing thedisorder or condition to which such term applies, or one or moresymptoms of such disorder or condition. The term “treatment”, as usedherein, refers to the act of treating, as “treating” is definedimmediately above. In some embodiments, the term “treatment” is intendedto mean the administration of a compound or composition according to thepresent invention to alleviate or eliminate symptoms of an Arenaviridaevirus infection and/or to reduce viral load in a patient. In someembodiments, the term “treatment” as used herein is further oralternatively intended to mean the administration of a compound orcomposition according to the present invention to alleviate or eliminatesymptoms of a Coronaviridae virus infection and/or to reduce viral loadin a patient. In some embodiments, the term “treatment” as used hereinis further or alternatively intended to mean the administration of acompound or composition according to the present invention to alleviateor eliminate symptoms of a Filoviridae virus infection and/or to reduceviral load in a patient. In some embodiments, the term “treatment” asused herein is further or alternatively intended to mean theadministration of a compound or composition according to the presentinvention to alleviate or eliminate symptoms of a Flaviviridae virusinfection and/or to reduce viral load in a patient. In some embodiments,the term “treatment” as used herein is further or alternatively intendedto mean the administration of a compound or composition according to thepresent invention to alleviate or eliminate symptoms of aParamyxoviridae virus infection and/or to reduce viral load in apatient. In some embodiments, the term “treatment” as used herein isfurther or alternatively intended to mean the administration of atherapeutically effective amount of a compound or composition accordingto the present invention to maintain a reduced viral load in a patient.

“Prevention” or “preventing” means any treatment of a disease orcondition that causes the clinical symptoms of the disease or conditionnot to develop. The term “prevention” also encompasses theadministration of a therapeutically effective amount of a compound orcomposition according to the present invention pre-exposure of theindividual to the virus (e.g., pre-exposure prophylaxis), to prevent theappearance of symptoms of the disease and/or to prevent the virus fromreaching detectible levels in the blood.

The terms “Subject” or “patient” refer to an animal, such as a mammal(including a human), that has been or will be the object of treatment,observation or experiment. The methods described herein may be useful inhuman therapy and/or veterinary applications. In some embodiments, thesubject is a mammal (or the patient). In some embodiments the subject(or the patient) is human, domestic animals (e.g., dogs and cats), farmanimals (e.g., cattle, horses, sheep, goats and pigs), and/or laboratoryanimals (e.g., mice, rats, hamsters, guinea pigs, pigs, rabbits, dogs,and monkeys). In some embodiments, the subject (or the patient) is ahuman. “Human (or patient) in need thereof” refers to a human who mayhave or is suspect to have diseases or conditions that would benefitfrom certain treatment; for example, being treated with the compoundsdisclosed herein according to the present application.

The term “antiviral agent” as used herein is intended to mean an agent(compound or biological) that is effective to inhibit the formationand/or replication of a virus in a human being, including but notlimited to agents that interfere with either host or viral mechanismsnecessary for the formation and/or replication of a virus in a humanbeing.

The term “inhibitor of Arenaviridae virus replication” as used herein isintended to mean an agent capable of reducing or eliminating the abilityof an Arenaviridae virus to replicate in a host cell, whether in vitro,ex vivo or in vivo.

The term “inhibitor of Coronaviridae virus replication” as used hereinis intended to mean an agent capable of reducing or eliminating theability of a Coronaviridae virus to replicate in a host cell, whether invitro, ex vivo or in vivo.

The term “inhibitor of Filoviridae virus replication” as used herein isintended to mean an agent capable of reducing or eliminating the abilityof a Filoviridae virus to replicate in a host cell, whether in vitro, exvivo or in vivo.

The term “inhibitor of Flaviviridae virus replication” as used herein isintended to mean an agent capable of reducing or eliminating the abilityof a Flaviviridae virus to replicate in a host cell, whether in vitro,ex vivo or in vivo.

The term “inhibitor of Paramyxoviridae virus replication” as used hereinis intended to mean an agent capable of reducing or eliminating theability of a Paramyxoviridae virus to replicate in a host cell, whetherin vitro, ex vivo or in vivo.

A “tautomer” refers to a proton shift from one atom of a molecule toanother atom of the same molecule. The present invention includestautomers of any said compounds.

Reference to “about” a value or parameter herein includes (anddescribes) embodiments that are directed to that value or parameter perse. For example, description referring to “about X” includes descriptionof “X”. Also, the singular forms “a” and “the” include plural referencesunless the context clearly dictates otherwise. Thus, e.g., reference to“the compound” includes a plurality of such compounds and reference to“the assay” includes reference to one or more assays and equivalentsthereof known to those skilled in the art.

“Pharmaceutically acceptable” or “physiologically acceptable” refer tocompounds, salts, compositions, dosage forms and other materials whichare useful in preparing a pharmaceutical composition that is suitablefor veterinary or human pharmaceutical use.

“Unit dosage forms” are physically discrete units suitable as unitarydosages for subjects (e.g., human subjects and other mammals), each unitcontaining a predetermined quantity of active material calculated toproduce the desired therapeutic effect, in association with a suitablepharmaceutical excipient.

The term “substantially as shown in” when referring, for example, to anXRPD pattern, a DSC thermogram, DVS graphs, or a TGA graph includes apattern, thermogram or graph that is not necessarily identical to thosedepicted herein, but that falls within the limits of experimental erroror deviations when considered by one of ordinary skill in the art.Mixtures I-III are understood have different ratios of Formula I Form IIto Formula I Form IV (Formula I Form II:Formula I Form IV). Accordingly,one of ordinary skill in the art would appreciate that other mixtures ofFormula I Form II and Formula I Form IV may exist with datasubstantially as shown in the XRPD patterns, DSC thermograms, or TGAgraphs provided herein, wherein the “substantially as shown” refers to avariance in purity of a Formula I Form II and Formula I Form IV mixture.

In some embodiments, the term “substantially pure” or “substantiallyfree” with respect to a particular crystalline form of a compound meansthat the composition comprising the crystalline form contains less than99%, less than 95%, less than 90%, less than 85%, less than 80%, lessthan 75%, less than 70%, less than 65%, less than 60%, less than 55%,less than 50%, less than 40%, less than 30%, less than 20%, less than15%, less than 10%, less than 5%, or less than 1% by weight of othersubstances, including other crystalline forms and/or impurities. In someembodiments, “substantially pure” or “substantially free of” refers to asubstance free of other substances, including other crystalline formsand/or impurities. Impurities may, for example, include by-products orleft over reagents from chemical reactions, contaminants, degradationproducts, other crystalline forms, water, and solvents.

III. Crystalline Forms

A. Formula I

It is desirable to develop a crystalline form of Formula I that may beuseful in the synthesis of a compound of Formula I. A crystalline formof a Formula I may be an intermediate to the synthesis of Formula I. Acrystalline form may have properties such as bioavailability, stability,purity, and/or manufacturability at certain conditions that may besuitable for medical or pharmaceutical uses.

Crystalline forms of Formula I, including substantially pure forms andmixtures of substantially pure forms, may provide the advantage ofbioavailability and stability, suitable for use as an active ingredientin a pharmaceutical composition. Variations in the crystal structure ofa pharmaceutical drug substance or active ingredient may affect thedissolution rate (which may affect bioavailability, etc.),manufacturability (e.g., ease of handling, ability to consistentlyprepare doses of known strength), and stability (e.g., thermalstability, shelf life, etc.) of a pharmaceutical drug product or activeingredient. Such variations may affect the preparation or formulation ofpharmaceutical compositions in different dosage or delivery forms, suchas solutions or solid oral dosage form including tablets and capsules.Compared to other forms such as non-crystalline or amorphous forms,crystalline forms may provide desired or suitable hygroscopicity,particle size controls, dissolution rate, solubility, purity, physicaland chemical stability, manufacturability, yield, and/or processcontrol. Thus, crystalline forms of Formula I may provide advantagessuch as: improving the manufacturing process of an active agent or thestability or storability of a drug product form of the compound or anactive ingredient, and/or having suitable bioavailability and/orstability as an active agent.

The use of certain solvents and/or processes have been found to producedifferent crystalline forms of Formula I described herein which mayexhibit one or more favorable characteristics described above. Theprocesses for the preparation of the crystalline forms described herein,and characterization of these crystalline forms are described in greaterdetail below.

The compound name provided above is named according to IUPAC rules orusing ChemBioDraw Ultra and one skilled in the art understands that thecompound structure may be named or identified using other commonlyrecognized nomenclature systems and symbols. By way of example, thecompound may be named or identified with common names, systematic ornon-systematic names. The nomenclature systems and symbols that arecommonly recognized in the art of chemistry including but not limited toChemical Abstract Service (CAS) and International Union of Pure andApplied Chemistry (IUPAC). Accordingly, the compound structure providedabove may also be named or identified as (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate under IUPAC, as 2-ethylbutyl((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninateaccording to ChemBioDraw Ultra, and as CAS Registry Number 1809249-37-3.

In particular embodiments, crystalline forms of Formula I are disclosed.

Formula I Form I

In some embodiments, provided is crystalline Form I of Formula I(crystalline Formula I Form I), wherein the crystal structure exhibitsan X-ray powder diffraction (XRPD) pattern substantially as shown inFIG. 1. Crystalline Formula I Form I may exhibit a differential scanningcalorimetry (DSC) thermogram substantially as shown in FIG. 2.Crystalline Formula I Form I may exhibit a thermogravimetric analysis(TGA) graph substantially as shown in FIG. 3. Crystalline Formula I FormI may exhibit dynamic vapor sorption (DVS) graphs substantially as shownin FIG. 4.

In some embodiments of crystalline Formula I Form I, at least one, atleast two, at least three, at least four, or all of the following(a)-(d) apply: (a) crystalline Formula I Form I has an XRPD patternsubstantially as shown in FIG. 1; (b) crystalline Formula I Form I has aDSC thermogram substantially as shown in FIG. 2; (c) crystalline FormulaI Form I has a TGA graph substantially as shown in FIG. 3; (d)crystalline Formula I Form I has DVS graphs substantially as shown inFIG. 4.

In some embodiments, crystalline Formula I Form I has the followingproperties:

-   -   (a) an XRPD pattern substantially as shown in FIG. 1;    -   (b) a DSC thermogram substantially as shown in FIG. 2;    -   (c) a TGA graph substantially as shown in FIG. 3; and    -   (d) DVS graphs substantially as shown in FIG. 4.

In some embodiments, crystalline Formula I Form I has an XRPD patterndisplaying at least two, at least three, at least four, at least five,or at least six of the degree 2θ-reflections with the greatest intensityas the XRPD pattern substantially as shown in FIG. 1.

In some embodiments, crystalline Formula I Form I has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 5.3°, 20.6°, and22.7°. In some embodiments, crystalline Formula I Form I has an XRPDpattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 5.3°,20.6°, and 22.7° and one or more of the degree 2θ-reflections (+/−0.2degrees 2θ) at 17.1° and 20.0°. In some embodiments, crystalline FormulaI Form I has an XRPD pattern comprising degree 2θ-reflections (+/−0.2degrees 2θ) at 5.3°, 20.6°, and 22.7° and one of the degree2θ-reflections (+/−0.2 degrees 2θ) at 17.1° and 20.0°. In someembodiments, crystalline Formula I Form I has an XRPD pattern comprisingdegree 2θ-reflections (+/−0.2 degrees 2θ) at 5.3°, 20.6°, and 22.7° andtwo of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 17.1° and 20.0°.In some embodiments, crystalline Formula I Form I has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 5.3°, 20.6°,22.7°, 17.1° and 20.0°. In some embodiments, crystalline Formula I FormI has an XRPD pattern comprising any three degree 2θ-reflections (+/−0.2degrees 2θ) selected from the group consisting of 5.3°, 20.6°, 22.7°,17.1° and 20.0°.

In some embodiments, crystalline Formula I Form I has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 5.3°, 20.6°,22.7°, 17.1° and 20.0° and one or more of the degree 2θ-reflections(+/−0.2 degrees 2θ) at 17.6°, 16.3°, and 13.7°. In some embodiments,crystalline Formula I Form I has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 5.3°, 20.6°, 22.7°, 17.1° and20.0° and one of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 17.6°,16.3°, and 13.7°. In some embodiments, crystalline Formula I Form I hasan XRPD pattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at5.3°, 20.6°, 22.7°, 17.1° and 20.0° and two of the degree 2θ-reflections(+/−0.2 degrees 2θ) at 17.6°, 16.3°, and 13.7°. In some embodiments,crystalline Formula I Form I has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 5.3°, 20.6°, 22.7°, 17.1°, 20.0°,17.6°, 16.3°, and 13.7°. In some embodiments, crystalline Formula I FormI has an XRPD pattern comprising any three degree 2θ-reflections (+/−0.2degrees 2θ) selected from the group consisting of 5.3°, 20.6°, 22.7°,17.1°, 20.0°, 17.6°, 16.3°, and 13.7°.

Formula I Form II

In some embodiments, provided is crystalline Form II of Formula I(crystalline Formula I Form II), wherein the crystal structure exhibitsan X-ray powder diffraction (XRPD) pattern substantially as shown inFIG. 5. Crystalline Formula I Form II may exhibit a differentialscanning calorimetry (DSC) thermogram substantially as shown in FIG. 6.Crystalline Formula I Form II may exhibit a thermogravimetric analysis(TGA) graph substantially as shown in FIG. 7. Crystalline Formula I FormII may exhibit dynamic vapor sorption (DVS) graphs substantially asshown in FIG. 8.

Crystalline Formula I Form II may have a unit cell as determined bysingle crystal X-ray crystallography of the following dimensions:a=10.505 (2) Å; b=12.736 (3) Å; c=11.066 (2) Å; α=90°; β=100.105 (7) °;and γ=90°.

In some embodiments of crystalline Formula I Form II, at least one, atleast two, at least three, at least four, at least five, or all of thefollowing (a)-(e) apply: (a) crystalline Formula I Form II has a unitcell, as determined by crystal X-ray crystallography at a temperature of100 K, of the following dimensions: a=10.505 (2) Å; b=12.736 (3) Å;c=11.066 (2) Å; α=90°; β=100.105 (7) °; and γ=90°; (b) crystallineFormula I Form II has an XRPD pattern substantially as shown in FIG. 5;(c) crystalline Formula I Form II has a DSC thermogram substantially asshown in FIG. 6; (d) crystalline Formula I Form II has a TGA graphsubstantially as shown in FIG. 7; (e) crystalline Formula I Form II hasDVS graphs substantially as shown in FIG. 8. In some embodiments ofcrystalline Formula I Form II, at least one, at least two, at leastthree, at least four, at least five, or all of the following (a)-(f)apply: (a) crystalline Formula I Form II has a unit cell, as determinedby crystal X-ray crystallography at a temperature of 100 K, of thefollowing dimensions: a=10.505 (2) Å; b=12.736 (3) Å; c=11.066 (2) Å;α=90°; β=100.105 (7) °; and γ=90°; (b) crystalline Formula I Form II hasan XRPD pattern substantially as shown in FIG. 5; (c) crystallineFormula I Form II has a DSC thermogram substantially as shown in FIG. 6;(d) crystalline Formula I Form II has a TGA graph substantially as shownin FIG. 7; (e) crystalline Formula I Form II has DVS graphssubstantially as shown in FIG. 8; (f) crystalline Formula I Form II hasa solid state NMR substantially as shown in FIG. 27.

In some embodiments, crystalline Formula I Form II has the followingproperties:

-   -   (a) a unit cell, as determined by crystal X-ray crystallography        at a temperature of 100 K, of the following dimensions        a=10.505 (2) Å; b=12.736 (3) Å; c=11.066 (2) Å; α=90°;        β=100.105 (7) °; and γ=90°;    -   (b) an XRPD pattern substantially as shown in FIG. 5;    -   (c) a DSC thermogram substantially as shown in FIG. 6;    -   (d) a TGA graph substantially as shown in FIG. 7; and    -   (e) DVS graphs substantially as shown in FIG. 8.

In some embodiments, crystalline Formula I Form II has the followingproperties:

-   -   (a) a unit cell, as determined by crystal X-ray crystallography        at a temperature of 100 K, of the following dimensions        a=10.505 (2) Å; b=12.736 (3) Å; c=11.066 (2) Å; α=90°;        β=100.105 (7) °; and γ=90°;    -   (b) an XRPD pattern substantially as shown in FIG. 5;    -   (c) a DSC thermogram substantially as shown in FIG. 6;    -   (d) a TGA graph substantially as shown in FIG. 7;    -   (e) DVS graphs substantially as shown in FIG. 8; and    -   (f) a solid state NMR substantially as shown in FIG. 27.

In some embodiments, crystalline Formula I Form II has the followingproperties:

-   -   an X-ray powder diffraction (XRPD) pattern having peaks at about        22.3°, 16.9°, 16.2°, 13.8°, 12.7°, 22.5°, 10.6° and 14.5°        2-0±0.2° 2-0;    -   a Differential Scanning calorimetry (DSC) thermogram peak at        138° C.; and    -   a unit cell as determined by single crystal X-ray        crystallography of the following dimensions: a=10.505 (2) Å;        b=12.736 (3) Å; c=11.066 (2) Å; α=90°; β=100.105 (7) °; and        γ=90°.

In some embodiments, crystalline Formula I Form II has an XRPD patterndisplaying at least two, at least three, at least four, at least five,or at least six of the degree 2θ-reflections with the greatest intensityas the XRPD pattern substantially as shown in FIG. 5.

In some embodiments, crystalline Formula I Form II has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 22.3°, 16.9°,and 16.2°. In some embodiments, crystalline Formula I Form II has anXRPD pattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at22.3°, 16.9°, and 16.2° and one or more of the degree 2θ-reflections(+/−0.2 degrees 2θ) at 13.8° and 12.7°. In some embodiments, crystallineFormula I Form II has an XRPD pattern comprising degree 2θ-reflections(+/−0.2 degrees 2θ) at 22.3°, 16.9°, and 16.2° and one of the degree2θ-reflections (+/−0.2 degrees 2θ) at 13.8° and 12.7°. In someembodiments, crystalline Formula I Form II has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 22.3°, 16.9°,and 16.2° and two of the degree 2θ-reflections (+/−0.2 degrees 2θ) at13.8° and 12.7°. In some embodiments, crystalline Formula I Form II hasan XRPD pattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at22.3°, 16.9°, 16.2°, 13.8° and 12.7°. In some embodiments, crystallineFormula I Form II has an XRPD pattern comprising any three degree2θ-reflections (+/−0.2 degrees 2θ) selected from the group consisting of22.3°, 16.9°, 16.2°, 13.8°, and 12.7°.

In some embodiments, crystalline Formula I Form II has an XRPD patternfurther comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 22.5°,10.6° and 14.5°. In some embodiments, crystalline Formula I Form II hasan XRPD pattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at22.3°, 16.9°, 16.2°, 13.8° and 12.7° and one or more of the degree2θ-reflections (+/−0.2 degrees 2θ) at 22.5°, 10.6° and 14.5°. In someembodiments, crystalline Formula I Form II has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 22.3°, 16.9°,16.2°, 13.8° and 12.7° and one of the degree 2θ-reflections (+/−0.2degrees 2θ) at 22.5°, 10.6° and 14.5°. In some embodiments, crystallineFormula I Form II has an XRPD pattern comprising degree 2θ-reflections(+/−0.2 degrees 2θ) at 22.3°, 16.9°, 16.2°, 13.8° and 12.7° and two ofthe degree 2θ-reflections (+/−0.2 degrees 2θ) at 22.5°, 10.6° and 14.5°.In some embodiments, crystalline Formula I Form II has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 22.3°, 16.9°,16.2°, 13.8°, 12.7°, 22.5°, 10.6° and 14.5°. In some embodiments,crystalline Formula I Form II has an XRPD pattern comprising any threedegree 2θ-reflections (+/−0.2 degrees 2θ) selected from the groupconsisting of 22.3°, 16.9°, 16.2°, 13.8°, 12.7°, 22.5°, 10.6° and 14.5°.

Formula I Form III

In some embodiments, provided is crystalline Form III of Formula I(crystalline Formula I Form III), wherein the crystal structure exhibitsa calculated powder pattern substantially as shown in FIG. 9.

Crystalline Formula I Form III may have a unit cell as determined bysingle crystal X-ray crystallography of the following dimensions:a=10.5800 (4) A; b=7.4526 (4) A; c=21.5691 (12) Å; α=90°; β=92.500 (3)°; and γ=90°.

In some embodiments of crystalline Formula I Form III, at least one, atleast two, at least three, at least four, at least five, at least six,at least seven, or all of the following (a)-(g) apply: (a) crystallineForm III has a calculated powder pattern substantially as shown in FIG.9; (b) crystalline Formula I Form III has a unit cell, as determined bycrystal X-ray crystallography at a temperature of 100 K, of thefollowing dimensions: a=10.5800 (4) Å; b=7.4526 (4) Å; c=21.5691 (12) Å;α=90°; β=92.500 (3) °; and γ=90°; (c) crystalline Formula I Form III hasa monoclinic crystal system; (d) crystalline Formula I Form III has a P21 space group; (e) crystalline Formula I Form III has a volume of3884.0(8) Å³; (f) crystalline Formula I Form III has a Z value of 2; and(g) crystalline Formula I Form III has a density of 1.348 Mg/m³.

In some embodiments, crystalline Formula I Form III has the followingproperties:

-   -   (a) a calculated powder pattern substantially as shown in FIG.        9; and    -   (b) a unit cell, as determined by crystal X-ray crystallography        at a temperature of 100 K, of the following dimensions        a=10.5800 (4) Å; b=7.4526 (4) Å; c=21.5691 (12) Å; α=90°;        β=92.500 (3) °; and γ=90°.

In some embodiments, crystalline Formula I Form III has a calculatedpowder pattern displaying at least two, at least three, at least four,at least five, or at least six of the degree 2θ-reflections with thegreatest intensity as the calculated powder pattern substantially asshown in FIG. 9.

In some embodiments, crystalline Formula I Form III has a calculatedpowder pattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at4.1°, 8.2°, 17.1°, and 23.8°. In some embodiments, crystalline FormFormula I III has a calculated powder pattern comprising any threedegree 2θ-reflections (+/−0.2 degrees 2θ) selected from the groupconsisting of 4.1°, 8.2°, 17.1°, and 23.8°.

In some embodiments, crystalline Formula I Form III has a calculatedpowder pattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at4.1°, 8.2°, 17.1°, and 23.8° and one or more of the degree2θ-reflections (+/−0.2 degrees 2θ) at 16.9°, 14.4° and 25.6°. In someembodiments, crystalline Formula I Form III has a calculated powderpattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 4.1°,8.2°, 17.1°, and 23.8° and one of the degree 2θ-reflections (+/−0.2degrees 2θ) at 16.9°, 14.4° and 25.6°. In some embodiments, crystallineFormula I Form III has a calculated powder pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 4.1°, 8.2°, 17.1°, and 23.8° andtwo of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 16.9°, 14.4° and25.6°. In some embodiments, crystalline Formula I Form III has acalculated powder pattern comprising degree 2θ-reflections (+/−0.2degrees 2θ) at 4.1°, 8.2°, 17.1°, 23.8°, 16.9°, 14.4° and 25.6°.

Formula I Form IV

In some embodiments, provided is crystalline Form IV of Formula I(crystalline Formula I Form IV), wherein the crystal structure exhibitsan X-ray powder diffraction (XRPD) pattern substantially as shown inFIG. 10. Crystalline Formula I Form IV may exhibit a differentialscanning calorimetry (DSC) thermogram substantially as shown in FIG. 11.Crystalline Formula I Form IV may exhibit a thermogravimetric analysis(TGA) graph substantially as shown in FIG. 12.

In some embodiments of crystalline Formula I Form IV, at least one, atleast two, or all of the following (a)-(c) apply: (a) crystallineFormula I Form IV has an XRPD pattern substantially as shown in FIG. 10;(b) crystalline Formula I Form IV has a DSC thermogram substantially asshown in FIG. 11; (c) crystalline Formula I Form IV has a TGA graphsubstantially as shown in FIG. 12.

In some embodiments, crystalline Formula I Form IV has the followingproperties:

-   -   (a) an XRPD pattern substantially as shown in FIG. 10;    -   (b) a DSC thermogram substantially as shown in FIG. 11; and    -   (c) a TGA graph substantially as shown in FIG. 12.

In some embodiments, crystalline Formula I Form IV has an XRPD patterndisplaying at least two, at least three, at least four, at least five,or at least six of the degree 2θ-reflections with the greatest intensityas the XRPD pattern substantially as shown in FIG. 10.

In some embodiments, crystalline Formula I Form IV has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 22.6°, 19.9°,and 14.1°. In some embodiments, crystalline Formula I Form IV has anXRPD pattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at22.6°, 19.9°, and 14.1° and one or more of the degree 2θ-reflections(+/−0.2 degrees 2θ) at 17.4°, 8.0°, and 12.5°. In some embodiments,crystalline Formula I Form IV has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 22.6°, 19.9°, and 14.1° and one ofthe degree 2θ-reflections (+/−0.2 degrees 2θ) at 17.4°, 8.0°, and 12.5°.In some embodiments, crystalline Formula I Form IV has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 22.6°, 19.9°,and 14.1° and two of the degree 2θ-reflections (+/−0.2 degrees 2θ) at17.4°, 8.0°, and 12.5°. In some embodiments, crystalline Formula I FormIV has an XRPD pattern comprising degree 2θ-reflections (+/−0.2 degrees2θ) at 22.6°, 19.9°, and 14.1° and three of the degree 2θ-reflections(+/−0.2 degrees 2θ) at 17.4°, 8.0°, and 12.5°. In some embodiments,crystalline Formula I Form IV has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 22.6°, 19.9°, 14.1°, 17.4°, 8.0°,and 12.5°. In some embodiments, crystalline Formula I Form IV has anXRPD pattern comprising any three degree 2θ-reflections (+/−0.2 degrees2θ) selected from the group consisting of 22.6°, 19.9°, 14.1°, 17.4°,8.0°, and 12.5°.

B. Mixtures of Forms of Formula I

Mixture I

In some embodiments, provided is a mixture of Forms II and IV of FormulaI (Mixture I), wherein the crystal structure exhibits an X-ray powderdiffraction (XRPD) pattern substantially as shown in FIG. 13. Mixture Imay exhibit a differential scanning calorimetry (DSC) thermogramsubstantially as shown in FIG. 14. Mixture I may exhibit athermogravimetric analysis (TGA) graph substantially as shown in FIG.15.

In some embodiments of Mixture I, at least one, at least two, or all ofthe following (a)-(c) apply: (a) Mixture I has an XRPD patternsubstantially as shown in FIG. 13; (b) Mixture I has a DSC thermogramsubstantially as shown in FIG. 14; (c) Mixture I has a TGA graphsubstantially as shown in FIG. 15.

In some embodiments, Mixture I has the following properties:

-   -   (a) an XRPD pattern substantially as shown in FIG. 13;    -   (b) a DSC thermogram substantially as shown in FIG. 14; and    -   (c) a TGA graph substantially as shown in FIG. 15.

In some embodiments, Mixture I has an XRPD pattern displaying at leasttwo, at least three, or at least four of the degree 2θ-reflections withthe greatest intensity as the XRPD pattern substantially as shown inFIG. 13.

In some embodiments, Mixture I has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 15.9°, 22.6°, and 14.1°. In someembodiments, Mixture I has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 15.9°, 22.6°, and 14.1° and thedegree 2θ-reflection (+/−0.2 degrees 2θ) at 12.5°. In some embodiments,Mixture I has an XRPD pattern comprising degree 2θ-reflections (+/−0.2degrees 2θ) at 15.9°, 22.6°, 14.1°, and 12.5°. In some embodiments,Mixture I has an XRPD pattern comprising any three degree 2θ-reflections(+/−0.2 degrees 2θ) selected from the group consisting of 15.9°, 22.6°,14.1°, and 12.5°.

Mixture II

In some embodiments, provided is a mixture of Forms II and IV of FormulaI (Mixture II), wherein the crystal structure exhibits an X-ray powderdiffraction (XRPD) pattern substantially as shown in FIG. 16. Mixture IImay exhibit a differential scanning calorimetry (DSC) thermogramsubstantially as shown in FIG. 17. Mixture II may exhibit athermogravimetric analysis (TGA) graph substantially as shown in FIG.18.

In some embodiments of Mixture II, at least one, at least two, or all ofthe following (a)-(c) apply: (a) Mixture II has an XRPD patternsubstantially as shown in FIG. 16; (b) Mixture II has a DSC thermogramsubstantially as shown in FIG. 17; (c) Mixture II has a TGA graphsubstantially as shown in FIG. 18.

In some embodiments, Mixture II has the following properties:

-   -   (a) an XRPD pattern substantially as shown in FIG. 16;    -   (b) a DSC thermogram substantially as shown in FIG. 17; and    -   (c) a TGA graph substantially as shown in FIG. 18.

In some embodiments, Mixture II has an XRPD pattern displaying at leasttwo, at least three, at least four, at least five, at least six, atleast seven, at least eight, at least nine, at least ten, at leasteleven, at least twelve of the degree 2θ-reflections with the greatestintensity as the XRPD pattern substantially as shown in FIG. 16.

In some embodiments, Mixture II has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 16.1°, 22.4°, and 12.7°. In someembodiments, Mixture II has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 16.1°, 22.4°, and 12.7° and one ormore of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 24.2°, 16.8°,and 8.1°. In some embodiments, Mixture II has an XRPD pattern comprisingdegree 2θ-reflections (+/−0.2 degrees 2θ) at 16.1°, 22.4°, and 12.7° andone of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 24.2°, 16.8°,and 8.1°. In some embodiments, Mixture II has an XRPD pattern comprisingdegree 2θ-reflections (+/−0.2 degrees 2θ) at 16.1°, 22.4°, and 12.7° andtwo of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 24.2°, 16.8°,and 8.1°. In some embodiments, Mixture II has an XRPD pattern comprisingdegree 2θ-reflections (+/−0.2 degrees 2θ) at 16.1°, 22.4°, and 12.7° andthree of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 24.2°, 16.8°,and 8.1°. In some embodiments, Mixture II has an XRPD pattern comprisingdegree 2θ-reflections (+/−0.2 degrees 2θ) at 16.1°, 22.4°, 12.7°, 24.2°,16.8°, and 8.1°. In some embodiments, Mixture II has an XRPD patterncomprising any three degree 2θ-reflections (+/−0.2 degrees 2θ) selectedfrom the group consisting of 16.1°, 22.4°, 12.7°, 24.2°, 16.8°, 8.1°,13.9°, 17.5°, 11.1°, 10.7°, 14.7°, and 19.8°.

Mixture III

In some embodiments, provided is a mixture of Forms II and IV of FormulaI (Mixture III), wherein the crystal structure exhibits an X-ray powderdiffraction (XRPD) pattern substantially as shown in FIG. 19. MixtureIII may exhibit a differential scanning calorimetry (DSC) thermogramsubstantially as shown in FIG. 20. Mixture III may exhibit athermogravimetric analysis (TGA) graph substantially as shown in FIG.21.

In some embodiments of Mixture III, at least one, at least two, or allof the following (a)-(c) apply: (a) Mixture III has an XRPD patternsubstantially as shown in FIG. 19; (b) Mixture III has a DSC thermogramsubstantially as shown in FIG. 20; (c) Mixture III has a TGA graphsubstantially as shown in FIG. 21.

In some embodiments, Mixture III has the following properties:

-   -   (a) an XRPD pattern substantially as shown in FIG. 19;    -   (b) a DSC thermogram substantially as shown in FIG. 20; and    -   (c) a TGA graph substantially as shown in FIG. 21.

In some embodiments, Mixture III has an XRPD pattern displaying at leasttwo, at least three, at least four, or at least five of the degree2θ-reflections with the greatest intensity as the XRPD patternsubstantially as shown in FIG. 19.

In some embodiments, Mixture III has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 16.7°, 12.6°, and 17.2°. In someembodiments, Mixture III has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 16.7°, 12.6°, and 17.2° and one ormore of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 19.6° and14.1°. In some embodiments, Mixture III has an XRPD pattern comprisingdegree 2θ-reflections (+/−0.2 degrees 2θ) at 16.7°, 12.6°, and 17.2° andone of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 19.6° and 14.1°.In some embodiments, Mixture III has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 16.7°, 12.6°, and 17.2° and two ofthe degree 2θ-reflections (+/−0.2 degrees 2θ) at 19.6° and 14.1°. Insome embodiments, Mixture III has an XRPD pattern comprising degree2θ-reflections (+/−0.2 degrees 2θ) at 16.7°, 12.6°, 17.2°, 19.6° and14.1°. In some embodiments, Mixture III has an XRPD pattern comprisingany three degree 2θ-reflections (+/−0.2 degrees 2θ) selected from thegroup consisting of 16.7°, 12.6°, 17.2°, 19.6° and 14.1°.

C. Formula I Maleate Form I

In some embodiments, provided is crystalline Formula I Maleate(crystalline Formula I Maleate Form I), wherein the crystal structureexhibits an X-ray powder diffraction (XRPD) pattern substantially asshown in FIG. 22. Crystalline Formula I Maleate Form I may exhibit adifferential scanning calorimetry (DSC) thermogram substantially asshown in FIG. 23. Crystalline Formula I Maleate Form I may exhibit athermogravimetric analysis (TGA) graph substantially as shown in FIG.24. Crystalline Formula I Maleate Form I may exhibit dynamic vaporsorption (DVS) graphs substantially as shown in FIG. 25.

In some embodiments of crystalline Formula I Maleate Form I, at leastone, at least two, at least three, or all of the following (a)-(d)apply: (a) crystalline Formula I Maleate Form I has an XRPD patternsubstantially as shown in FIG. 22; (b) crystalline Formula I MaleateForm I has a DSC thermogram substantially as shown in FIG. 23; (c)crystalline Formula I Maleate Form I has a TGA graph substantially asshown in FIG. 24; and (d) crystalline Formula I Maleate Form I has DVSgraphs substantially as shown in FIG. 25.

In some embodiments, crystalline Formula I Maleate Form I has thefollowing properties:

-   -   (a) an XRPD pattern substantially as shown in FIG. 22;    -   (b) a DSC thermogram substantially as shown in FIG. 23;    -   (c) TGA graphs substantially as shown in FIG. 24; and    -   (d) DVS graphs substantially as shown in FIG. 25.

In some embodiments, crystalline Formula I Maleate Form I has an XRPDpattern displaying at least two, at least three, at least four, at leastfive, or at least six of the degree 2θ-reflections with the greatestintensity as the XRPD pattern substantially as shown in FIG. 22.

In some embodiments, crystalline Formula I Maleate Form I has an XRPDpattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 16.3°,4.6°, and 9.0°. In some embodiments, crystalline Formula I Maleate FormI has an XRPD pattern comprising degree 2θ-reflections (+/−0.2 degrees2θ) at 16.3°, 4.6°, and 9.0° and one or more of the degree2θ-reflections (+/−0.2 degrees 2θ) 6.2° and 7.3°. In some embodiments,crystalline Formula I Maleate Form I has an XRPD pattern comprisingdegree 2θ-reflections (+/−0.2 degrees 2θ) at 16.3°, 4.6°, and 9.0° andone of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 6.2° and 7.3°.In some embodiments, crystalline Formula I Maleate Form I has an XRPDpattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 16.3°,4.6°, and 9.0° and two of the degree 2θ-reflections (+/−0.2 degrees 2θ)at 6.2° and 7.3°. In some embodiments, crystalline Formula I MaleateForm I has an XRPD pattern comprising degree 2θ-reflections (+/−0.2degrees 2θ) at 16.3°, 4.6°, 9.0°, 6.2° and 7.3°. In some embodiments,crystalline Formula I Maleate Form I has an XRPD pattern comprising anythree degree 2θ-reflections (+/−0.2 degrees 2θ) selected from the groupconsisting of 16.3°, 4.6°, 9.0°, 6.2° and 7.3°.

In some embodiments, crystalline Formula I Maleate Form I has an XRPDpattern comprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 16.3°,4.6°, 9.0°, 6.2° and 7.3° and one or more of the degree 2θ-reflections(+/−0.2 degrees 2θ) 17.8°, 15.1° and 14.7°. In some embodiments,crystalline Formula I Maleate Form I has an XRPD pattern comprisingdegree 2θ-reflections (+/−0.2 degrees 2θ) at 16.3°, 4.6°, 9.0°, 6.2° and7.3° and one of the degree 2θ-reflections (+/−0.2 degrees 2θ) at 17.8°,15.1° and 14.7°. In some embodiments, crystalline Formula I Maleate FormI has an XRPD pattern comprising degree 2θ-reflections (+/−0.2 degrees2θ) at 16.3°, 4.6°, 9.0°, 6.2° and 7.3° and two of the degree2θ-reflections (+/−0.2 degrees 2θ) at 17.8°, 15.1° and 14.7°. In someembodiments, crystalline Formula I Maleate Form I has an XRPD patterncomprising degree 2θ-reflections (+/−0.2 degrees 2θ) at 16.3°, 4.6°,9.0°, 6.2°, 7.3°, 17.8°, 15.1° and 14.7°. In some embodiments,crystalline Formula I Maleate Form I has an XRPD pattern comprising anythree degree 2θ-reflections (+/−0.2 degrees 2θ) selected from the groupconsisting of 16.3°, 4.6°, 9.0°, 6.2°, 7.3°, 17.8°, 15.1° and 14.7°.

IV. Pharmaceutical Compositions

For the purposes of administration, in some embodiments, the compoundsdescribed herein are administered as a raw chemical or are formulated aspharmaceutical compositions. Pharmaceutical compositions of the presentinvention comprise a therapeutically effective amount of a compound ofFormula I, including forms thereof, and a pharmaceutically acceptableexcipient. The compound of Formula I is present in the composition in anamount which is effective to treat a particular disease or condition ofinterest. The activity of compounds of Formula I can be determined byone skilled in the art, for example, as described herein. Appropriatetherapeutically effective concentrations and dosages can be readilydetermined by one skilled in the art. In some embodiments, a compound ofFormula I is present in the pharmaceutical composition in an amount fromabout 5 mg to about 300 mg. In some embodiments, a compound of Formula Iis present in the pharmaceutical composition in an amount of about 100mg to about 200 mg. In some embodiments, a compound of Formula I ispresent in the pharmaceutical composition in an amount of about 5 mg toabout 100 mg. In some embodiments, a compound of Formula I is present inthe pharmaceutical composition in an amount of about 5 mg to about 20mg. In some embodiments, a compound of Formula I is present in thepharmaceutical composition in an amount of about 130 mg to about 160 mg.In some embodiments, a compound of Formula I is present in thepharmaceutical composition in an amount of about 5 mg, 10 mg, 25 mg, 50mg, 75, mg, 100 mg, 150 mg, 200 mg, 250 mg, or about 300 mg. In someembodiments, a compound of Formula I is present in the pharmaceuticalcomposition in an amount of about 10 mg. In some embodiments, a compoundof Formula I is present in the pharmaceutical composition in an amountof about 150 mg. In some embodiments, a compound of Formula I is presentin the pharmaceutical composition in an amount of about 10 mg. In someembodiments, a compound of Formula I is present in the pharmaceuticalcomposition in an amount of about 150 mg.

Administration of the compounds of the invention in pure form or in anappropriate pharmaceutical composition, can be carried out via any ofthe accepted modes of administration of agents for serving similarutilities. The pharmaceutical compositions of the invention can beprepared by combining a compound of the invention with an appropriatepharmaceutically acceptable excipient, and may be formulated intopreparations in solid, semi-solid, liquid or gaseous forms, such astablets, capsules, powders, granules, ointments, solutions,suppositories, injections, inhalants, gels, microspheres, and aerosols.The pharmaceutical compositions of the invention can be prepared bycombining a compound of the invention with an appropriatepharmaceutically acceptable excipient, and may be formulated intopreparations in solid, semi-solid, liquid or gaseous forms, such assolid dispersions and solid solutions. Typical routes of administeringsuch pharmaceutical compositions include, without limitation, oral,topical, transdermal, inhalation, parenteral, sublingual, buccal,rectal, vaginal, and intranasal. In some embodiments, the pharmaceuticalcomposition is prepared for parental administration. In a specificembodiment, the pharmaceutical composition is a solution. Pharmaceuticalcompositions of the invention are formulated so as to allow the activeingredients contained therein to be bioavailable upon administration ofthe composition to a patient. Compositions that will be administered toa subject or patient take the form of one or more dosage units, wherefor example, a tablet may be a single dosage unit, and a container of acompound of the invention in aerosol form may hold a plurality of dosageunits. Actual methods of preparing such dosage forms are known, or willbe apparent, to those skilled in this art; for example, see Remington:The Science and Practice of Pharmacy, 20th Edition (Philadelphia Collegeof Pharmacy and Science, 2000). The composition to be administered will,in any event, contain a therapeutically effective amount of a compoundof the invention for treatment of a disease or condition of interest inaccordance with the teachings of this invention.

The pharmaceutical compositions of the invention may be prepared bymethodology well known in the pharmaceutical art. For example, apharmaceutical composition intended to be administered by injection canbe prepared by combining a compound of the invention with sterile,distilled water so as to form a solution. Alternatively, apharmaceutical composition intended to be administered by injection canbe prepared by combining a compound of the invention with sterile,reverse osmosis water so as to form a solution. A surfactant or othersolubilizing excipient may be added to facilitate the formation of ahomogeneous solution or suspension. Surfactants are compounds thatnon-covalently interact with the compound of the invention so as tofacilitate dissolution or homogeneous suspension of the compound in theaqueous delivery system.

In other embodiments, a solid pharmaceutical composition intended fororal administration can be prepared by mixing a therapeuticallyeffective amount of a compound of the invention with at least onesuitable pharmaceutically acceptable excipient to form a solidpreformulation composition, which then may be readily subdivided intoequally effective unit dosage forms such as tablets, pills and capsules.Accordingly, in some embodiments, a pharmaceutical composition isprovided, which includes a therapeutically effective amount of acompound of Formula I and a pharmaceutically acceptable excipient.

The compounds of the invention are administered in a therapeuticallyeffective amount, which will vary depending upon a variety of factorsincluding the activity of the specific compound employed; the metabolicstability and length of action of the compound; the age, body weight,general health, sex, and diet of the patient; the mode and time ofadministration; the rate of excretion; the drug combination; theseverity of the particular disorder or condition; and the subjectundergoing therapy. In some embodiments, the compounds of the inventioncan be administered alone or in combination with other antiviral agentsone time a day, or two times a day, or three times a day, or four timesa day, for as long as the patient is infected, latently infected, or toprevent infection (e.g. for multiple years, months, weeks, or days).

The compositions of the present invention can include the compound ofFormula I in any suitable purity. For example, the compound of Formula Ican have a purity of at least 99.0%, or at least 99.1, 99.2, 99.3, 99.4,99.5, 99.6, 99.7, 99.8 or at least 99.9%. In some embodiments, thepresent invention provides a composition having a compound of Formula Ihaving a purity of at least 99.1%. In some embodiments, the presentinvention provides a composition having a compound of Formula I having apurity of at least 99.3%. In some embodiments, the present inventionprovides a composition having a compound of Formula I having a purity ofat least 99.5%. In some embodiments, the present invention provides acomposition having a compound of Formula I having a purity of at least99.7%.

The impurities present in the compositions of the present invention caninclude unreacted starting material, undesirable side-products, andother materials. Representative impurities include Impurity A:

Impurity A can be present in the compositions of the present inventionin amount less than about 0.5% (w/w), or less than about 0.45%, 0.40,0.35, 0.30, 0.25, 0.20, 0.15, 0.10, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04,0.03, 0.02, or less than about 0.01% (w/w). In some embodiments, thecomposition of the compound of Formula I includes less than 0.10% (w/w)of Impurity A. In some embodiments, the composition of the compound ofFormula I includes less than 0.05% (w/w) of Impurity A.

In some embodiments, a composition of a compound of Formula I can have apurity of at least 99.1%, wherein the composition includes less than0.10% (w/w) of Impurity A. In some embodiments, a composition of acompound of Formula I can have a purity of at least 99.1%, wherein thecomposition includes less than 0.05% (w/w) of Impurity A. In someembodiments, a composition of a compound of Formula I can have a purityof at least 99.1%, wherein the composition includes less than 0.04%(w/w) of Impurity A. In some embodiments, a composition of a compound ofFormula I can have a purity of at least 99.5%, wherein the compositionincludes less than 0.04% (w/w) of Impurity A. In some embodiments, acomposition of a compound of Formula I can have a purity of at least99.5%, wherein the composition includes less than 0.04% (w/w) ofImpurity A.

Formula I

Provided are also compositions comprising at least one, at least two, atleast three or all crystalline forms of Formula I as described herein.In a particular embodiment, a composition comprising one compound ofFormula I described herein is provided. In a particular embodiment, acomposition comprising two crystalline compounds of Formula I describedherein is provided. In a particular embodiment, a composition comprisingthree crystalline compounds of Formula I described herein is provided.In a particular embodiment, a composition comprising four crystallinecompounds of Formula I described herein is provided. In a particularembodiment, a composition comprising a mixture of crystalline Formula IForm II and Formula I Form IV described herein. In other embodiments,the compositions described herein may comprise substantially purecrystalline forms, or may be substantially free of other crystallineforms and/or impurities.

In some embodiments, the composition comprises a crystalline form ofFormula I. In some embodiments are provided compositions comprising acrystalline form as described herein, wherein the compound of Formula Iwithin the composition is substantially pure (i.e., substantially purecompound of Formula I described herein). In particular embodiments ofcompositions comprising a crystalline form of Formula I, at least about50%, at least about 60%, at least about 70%, at least about 80%, atleast about 85%, at least about 90%, at least about 95%, at least about96%, at least about 97%, at least about 98%, or at least about 99% ofFormula I present in the composition is one of the crystalline formsdisclosed herein. In some embodiments, the composition includes at leastabout 50%, at least about 60%, at least about 70%, at least about 80%,at least about 85%, at least about 90%, at least about 95%, at leastabout 96%, at least about 97%, at least about 98%, or at least about 99%of one of the crystalline forms of Formula I.

In other embodiments of compositions comprising a crystalline formdisclosed herein, less than about 50%, less than about 40%, less thanabout 30%, less than about 20%, less than about 10%, less than about 5%,less than about 4%, less than about 3%, less than about 2% or less thanabout 1% of Formula I present in the composition are other amorphous orcrystal forms of Formula I and/or impurities.

In yet other embodiments of compositions comprising the crystallineforms disclosed herein, impurities make up less than about 5%, less thanabout 4%, less than about 3%, less than about 2% or less than about 1%of the total mass relative to the mass of the crystalline forms present.Impurities may, for example, include by-products from synthesizingFormula I, contaminants, degradation products, other crystalline forms,amorphous form, water, and solvents. In some embodiments, impuritiesinclude by-products from the process of synthesizing Formula I. In someembodiments, impurities include contaminants from the process ofsynthesizing Formula I. In some embodiments, impurities includedegradation products of Formula I. In some embodiments, impuritiesinclude other crystalline forms of Formula I. In some embodiments,impurities include water or solvent. In some embodiments of compositionscomprising a crystalline form disclosed herein, impurities are selectedfrom the group consisting of by-products from synthesizing Formula I,contaminants, degradation products, other crystalline forms, water,solvents and combinations thereof.

Combination Therapy

In some embodiments, a method for treating an Arenaviridae virusinfection in a human is provided, comprising administering to the humana therapeutically effective amount of a compound disclosed herein incombination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents. In some embodiments, a method for treating a Lassavirus infection in a human is provided, comprising administering to thehuman a therapeutically effective amount of a compound disclosed hereinin combination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents. In some embodiments, a method for treating a Juninvirus infection in a human is provided, comprising administering to thehuman a therapeutically effective amount of a compound disclosed hereinin combination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents.

In some embodiments, the present invention provides a method fortreating an Arenaviridae virus infection, comprising administering to apatient in need thereof a therapeutically effective amount of a compoundor composition disclosed herein in combination with a therapeuticallyeffective amount of one or more additional therapeutic agents which aresuitable for treating an Arenaviridae virus infection. In someembodiments, the present invention provides a method for treating aLassa virus infection, comprising administering to a patient in needthereof a therapeutically effective amount of a compound or compositiondisclosed herein in combination with a therapeutically effective amountof one or more additional therapeutic agents which are suitable fortreating an Arenaviridae virus infection. In some embodiments, thepresent invention provides a method for treating a Lassa virusinfection, comprising administering to a patient in need thereof atherapeutically effective amount of a compound or composition disclosedherein in combination with a therapeutically effective amount of one ormore additional therapeutic agents which are suitable for treating aLassa virus infection. In some embodiments, the present inventionprovides a method for treating a Junin virus infection, comprisingadministering to a patient in need thereof a therapeutically effectiveamount of a compound or composition disclosed herein in combination witha therapeutically effective amount of one or more additional therapeuticagents which are suitable for treating an Arenaviridae virus infection.In some embodiments, the present invention provides a method fortreating a Junin virus infection, comprising administering to a patientin need thereof a therapeutically effective amount of a compound orcomposition disclosed herein in combination with a therapeuticallyeffective amount of one or more additional therapeutic agents which aresuitable for treating a Junin virus infection.

Some embodiments provide a compound disclosed herein in combination withone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating anArenaviridae virus infection in a human having the infection. Someembodiments provide a therapeutically effective amount of a compounddisclosed herein in combination with therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating a Lassavirus infection in a human having the infection. Some embodimentsprovide a therapeutically effective amount of a compound disclosedherein in combination with therapeutically effective amount of one ormore (e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents for use in a method for treating a Junin virusinfection in a human having the infection. Some embodiments provide atherapeutically effective amount of a compound disclosed herein for usein a method for treating an Arenaviridae virus infection in a humanhaving the infection, wherein the compound is administered incombination with therapeutically effective amount of one or more (e.g.,one, two, three, one or two, or one to three) additional therapeuticagents. Some embodiments provide a compound disclosed herein for use ina method for treating a Lassa virus infection in a human having theinfection, wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents. Some embodiments provide a compounddisclosed herein for use in a method for treating a Junin virusinfection in a human having the infection, wherein a therapeuticallyeffective amount of the compound is administered in combination with atherapeutically effective amount of one or more (e.g., one, two, three,one or two, or one to three) additional therapeutic agents. In someembodiments, the present invention provides a compound disclosed hereinin combination with one or more additional therapeutic agents which aresuitable for treating an Arenaviridae virus infection, for use in amethod for treating an Arenaviridae virus infection. In someembodiments, the present invention provides a compound disclosed hereinfor use in a method for treating an Arenaviridae virus infection,wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more additional therapeutic agents which are suitable fortreating an Arenaviridae virus infection. In some embodiments, thepresent invention provides a compound disclosed herein in combinationwith one or more additional therapeutic agents which are suitable fortreating a Lassa virus infection, for use in a method for treating aLassa virus infection. In some embodiments, the present inventionprovides a compound disclosed herein for use in a method for treating aLassa virus infection, wherein a therapeutically effective amount of thecompound is administered in combination with a therapeutically effectiveamount of one or more additional therapeutic agents which are suitablefor treating a Lassa virus infection. In some embodiments, the presentinvention provides a compound disclosed herein in combination with oneor more additional therapeutic agents which are suitable for treating aJunin virus infection, for use in a method for treating a Junin virusinfection. In some embodiments, the present invention provides acompound disclosed herein for use in a method for treating a Junin virusinfection, wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more additional therapeutic agents which are suitable fortreating a Junin virus infection.

In some embodiments, a method for treating a Coronaviridae virusinfection in a human is provided, comprising administering to the humana therapeutically effective amount of a compound disclosed herein incombination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents. In some embodiments, a method for treating a SARSvirus infection in a human is provided, comprising administering to thehuman a therapeutically effective amount of a compound disclosed hereinin combination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents. In some embodiments, a method for treating a MERSvirus infection in a human is provided, comprising administering to thehuman a therapeutically effective amount of a compound disclosed hereinin combination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents.

In some embodiments, the present invention provides a method fortreating a Coronaviridae virus infection, comprising administering to apatient in need thereof a therapeutically effective amount of a compoundor composition disclosed herein in combination with a therapeuticallyeffective amount of one or more additional therapeutic agents which aresuitable for treating a Coronaviridae virus infection. In someembodiments, the present invention provides a method for treating a SARSvirus infection, comprising administering to a patient in need thereof atherapeutically effective amount of a compound or composition disclosedherein in combination with a therapeutically effective amount of one ormore additional therapeutic agents which are suitable for treating aCoronaviridae virus infection. In some embodiments, the presentinvention provides a method for treating a SARS virus infection,comprising administering to a patient in need thereof a therapeuticallyeffective amount of a compound or composition disclosed herein incombination with a therapeutically effective amount of one or moreadditional therapeutic agents which are suitable for treating a SARSvirus infection. In some embodiments, the present invention provides amethod for treating a MERS virus infection, comprising administering toa patient in need thereof a therapeutically effective amount of acompound or composition disclosed herein in combination with atherapeutically effective amount of one or more additional therapeuticagents which are suitable for treating a Coronaviridae virus infection.In some embodiments, the present invention provides a method fortreating a MERS virus infection, comprising administering to a patientin need thereof a therapeutically effective amount of a compound orcomposition disclosed herein in combination with a therapeuticallyeffective amount of one or more additional therapeutic agents which aresuitable for treating a MERS virus infection.

Some embodiments provide a compound disclosed herein in combination withone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating aCoronaviridae virus infection in a human having the infection. Someembodiments provide a therapeutically effective amount of a compounddisclosed herein in combination with therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating a SARSvirus infection in a human having the infection. Some embodimentsprovide a therapeutically effective amount of a compound disclosedherein in combination with therapeutically effective amount of one ormore (e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents for use in a method for treating a MERS virusinfection in a human having the infection. Some embodiments provide atherapeutically effective amount of a compound disclosed herein for usein a method for treating a Coronaviridae virus infection in a humanhaving the infection, wherein the compound is administered incombination with therapeutically effective amount of one or more (e.g.,one, two, three, one or two, or one to three) additional therapeuticagents. Some embodiments provide a compound disclosed herein for use ina method for treating a SARS virus infection in a human having theinfection, wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents. Some embodiments provide a compounddisclosed herein for use in a method for treating a MERS virus infectionin a human having the infection, wherein a therapeutically effectiveamount of the compound is administered in combination with atherapeutically effective amount of one or more (e.g., one, two, three,one or two, or one to three) additional therapeutic agents. In someembodiments, the present invention provides a compound disclosed hereinin combination with one or more additional therapeutic agents which aresuitable for treating a Coronaviridae virus infection, for use in amethod for treating a Coronaviridae virus infection. In someembodiments, the present invention provides a compound disclosed hereinfor use in a method for treating a Coronaviridae virus infection,wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more additional therapeutic agents which are suitable fortreating a Coronaviridae virus infection. In some embodiments, thepresent invention provides a compound disclosed herein in combinationwith one or more additional therapeutic agents which are suitable fortreating a SARS virus infection, for use in a method for treating a SARSvirus infection. In some embodiments, the present invention provides acompound disclosed herein for use in a method for treating a SARS virusinfection, wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more additional therapeutic agents which are suitable fortreating a SARS virus infection. In some embodiments, the presentinvention provides a compound disclosed herein in combination with oneor more additional therapeutic agents which are suitable for treating aMERS virus infection, for use in a method for treating a MERS virusinfection. In some embodiments, the present invention provides acompound disclosed herein for use in a method for treating a MERS virusinfection, wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more additional therapeutic agents which are suitable fortreating a MERS virus infection.

In some embodiments, a method for treating a Filoviridae virus infectionin a human is provided, comprising administering to the human atherapeutically effective amount of a compound disclosed herein incombination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents. In some embodiments, a method for treating anebolavirus infection in a human is provided, comprising administering tothe human a therapeutically effective amount of a compound disclosedherein in combination with a therapeutically effective amount of one ormore (e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents.

In some embodiments, the present invention provides a method fortreating a Filoviridae virus infection, comprising administering to apatient in need thereof a therapeutically effective amount of a compoundor composition disclosed herein in combination with a therapeuticallyeffective amount of one or more additional therapeutic agents which aresuitable for treating a Filoviridae virus infection. In someembodiments, the present invention provides a method for treating anebolavirus infection, comprising administering to a patient in needthereof a therapeutically effective amount of a compound or compositiondisclosed herein in combination with a therapeutically effective amountof one or more additional therapeutic agents which are suitable fortreating an ebolavirus infection.

Some embodiments provide a compound disclosed herein in combination withone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating aFiloviridae virus infection in a human having the infection. Someembodiments provide a therapeutically effective amount of a compounddisclosed herein in combination with therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating anebolavirus infection in a human having the infection. Some embodimentsprovide a therapeutically effective amount of a compound disclosedherein for use in a method for treating a Filoviridae virus infection ina human having the infection, wherein the compound is administered incombination with therapeutically effective amount of one or more (e.g.,one, two, three, one or two, or one to three) additional therapeuticagents. Some embodiments provide a compound disclosed herein for use ina method for treating an ebolavirus infection in a human having theinfection, wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents. In some embodiments, the presentinvention provides a compound disclosed herein in combination with oneor more additional therapeutic agents which are suitable for treating aFiloviridae virus infection, for use in a method for treating aFiloviridae virus infection. In some embodiments, the present inventionprovides a compound disclosed herein for use in a method for treating aFiloviridae virus infection, wherein a therapeutically effective amountof the compound is administered in combination with a therapeuticallyeffective amount of one or more additional therapeutic agents which aresuitable for treating a Filoviridae virus infection.

In some embodiments, a method for treating a Flaviviridae virusinfection in a human is provided, comprising administering to the humana therapeutically effective amount of a compound disclosed herein incombination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents. In some embodiments, a method for treating a Zikavirus infection in a human is provided, comprising administering to thehuman a therapeutically effective amount of a compound disclosed hereinin combination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents.

In some embodiments, the present invention provides a method fortreating a Flaviviridae virus infection, comprising administering to apatient in need thereof a therapeutically effective amount of a compoundor composition disclosed herein in combination with a therapeuticallyeffective amount of one or more additional therapeutic agents which aresuitable for treating a Flaviviridae virus infection. In someembodiments, the present invention provides a method for treating a Zikavirus infection, comprising administering to a patient in need thereof atherapeutically effective amount of a compound or composition disclosedherein in combination with a therapeutically effective amount of one ormore additional therapeutic agents which are suitable for treating aZika virus infection.

Some embodiments provide a compound disclosed herein in combination withone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating aFlaviviridae virus infection in a human having the infection. Someembodiments provide a therapeutically effective amount of a compounddisclosed herein in combination with therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating a Zikavirus infection in a human having the infection. Some embodimentsprovide a therapeutically effective amount of a compound disclosedherein for use in a method for treating a Flaviviridae virus infectionin a human having the infection, wherein the compound is administered incombination with therapeutically effective amount of one or more (e.g.,one, two, three, one or two, or one to three) additional therapeuticagents. Some embodiments provide a compound disclosed herein for use ina method for treating a Zika virus infection in a human having theinfection, wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents. In some embodiments, the presentinvention provides a compound disclosed herein in combination with oneor more additional therapeutic agents which are suitable for treating aFlaviviridae virus infection, for use in a method for treating aFlaviviridae virus infection. In some embodiments, the present inventionprovides a compound disclosed herein for use in a method for treating aFlaviviridae virus infection, wherein a therapeutically effective amountof the compound is administered in combination with a therapeuticallyeffective amount of one or more additional therapeutic agents which aresuitable for treating a Flaviviridae virus infection.

In some embodiments, a method for treating a Paramyxoviridae virusinfection in a human is provided, comprising administering to the humana therapeutically effective amount of a compound disclosed herein incombination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents. In some embodiments, a method for treating an RSVvirus infection in a human is provided, comprising administering to thehuman a therapeutically effective amount of a compound disclosed hereinin combination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents.

In some embodiments, the present invention provides a method fortreating a Paramyxoviridae virus infection, comprising administering toa patient in need thereof a therapeutically effective amount of acompound or composition disclosed herein in combination with atherapeutically effective amount of one or more additional therapeuticagents which are suitable for treating a Paramyxoviridae virusinfection. In some embodiments, the present invention provides a methodfor treating an RSV infection, comprising administering to a patient inneed thereof a therapeutically effective amount of a compound orcomposition disclosed herein in combination with a therapeuticallyeffective amount of one or more additional therapeutic agents which aresuitable for treating a RSV infection.

Some embodiments provide a compound disclosed herein in combination withone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating aParamyxoviridae virus infection in a human having the infection. Someembodiments provide a therapeutically effective amount of a compounddisclosed herein in combination with therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents for use in a method for treating an RSVinfection in a human having the infection. Some embodiments provide atherapeutically effective amount of a compound disclosed herein for usein a method for treating a Paramyxoviridae virus infection in a humanhaving the infection, wherein the compound is administered incombination with therapeutically effective amount of one or more (e.g.,one, two, three, one or two, or one to three) additional therapeuticagents. Some embodiments provide a compound disclosed herein for use ina method for treating an RSV infection in a human having the infection,wherein a therapeutically effective amount of the compound isadministered in combination with a therapeutically effective amount ofone or more (e.g., one, two, three, one or two, or one to three)additional therapeutic agents. In some embodiments, the presentinvention provides a compound disclosed herein in combination with oneor more additional therapeutic agents which are suitable for treating aParamyxoviridae virus infection, for use in a method for treating aParamyxoviridae virus infection. In some embodiments, the presentinvention provides a compound disclosed herein for use in a method fortreating a Paramyxoviridae virus infection, wherein a therapeuticallyeffective amount of the compound is administered in combination with atherapeutically effective amount of one or more additional therapeuticagents which are suitable for treating a Paramyxoviridae virusinfection.

A therapeutically effective amount of a compound of Formula I asdisclosed herein may be combined with a therapeutically effective amountof one or more additional therapeutic agents in any dosage amount of thecompound of Formula I (e.g., from 5 mg to 300 mg of compound).

In some embodiments, pharmaceutical compositions comprising atherapeutically effective amount of a compound disclosed herein incombination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents, and a pharmaceutically acceptable excipient areprovided.

In some embodiments, combination pharmaceutical agents comprising atherapeutically effective amount of a compound disclosed herein incombination with a therapeutically effective amount of one or more(e.g., one, two, three, one or two, or one to three) additionaltherapeutic agents are provided.

In some embodiments, kits comprising a therapeutically effective amountof a compound disclosed herein in combination with a therapeuticallyeffective amount of one or more (e.g., one, two, three, one or two, orone to three) additional therapeutic agents are provided.

In some embodiments, the additional therapeutic agent used incombination with a compound disclosed herein is active against virusinfections.

In some embodiments, the additional therapeutic agent used incombination with a compound disclosed herein is active againstArenaviridae virus infections, particularly Lassa virus and Junin virusinfections.

In some embodiments a therapeutically effective amount of a compound ofFormula I is formulated as a solution, which may optionally contain atherapeutically effective amount of one or more other compounds usefulfor treating an Arenaviridae virus infection. In some embodiments, thesolution can contain another active ingredient for treating anArenaviridae virus infection.

In some embodiments, the additional therapeutic agent used incombination with a compound disclosed herein is active againstCoronaviridae virus infections, particularly SARS virus and MERS virusinfections.

In some embodiments a therapeutically effective amount of a compound ofFormula I is formulated as a solution, which may optionally contain atherapeutically effective amount of one or more other compounds usefulfor treating a Coronaviridae virus infection. In some embodiments, thesolution can contain another active ingredient for treating aCoronaviridae virus infection.

In some embodiments, the additional therapeutic agent used incombination with a compound disclosed herein is active againstFiloviridae virus infections, particularly Marburg virus, ebolavirusand/or Cueva virus infections Non-limiting examples of these otheractive therapeutic agents are ribavirin, palivizumab, motavizumab,RSV-IGIV (RespiGam), MEDI-557, A-60444, MDT-637, BMS-433771, amiodarone,dronedarone, verapamil, Ebola Convalescent Plasma (ECP), TKM-100201,BCX4430((2S,3S,4R,5R)-2-(4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)-5-(hydroxymethyl)pyrrolidine-3,4-diol),favipiravir (also known as T-705 or Avigan), T-705 monophosphate, T-705diphosphate, T-705 triphosphate, FGI-106(1-N,7-N-bis[3-(dimethylamino)propyl]-3,9-dimethylquinolino[8,7-h]quinolone-1,7-diamine),JK-05, TKM-Ebola, ZMapp, rNAPc2, VRC-EBOADC076-00-VP, OS-2966, MVA-BNfilo, brincidofovir, Vaxart adenovirus vector 5-based ebola vaccine,Ad26-ZEBOV, FiloVax vaccine, GOVX-E301, GOVX-E302, ebola virus entryinhibitors (NPC1 inhibitors), and rVSV-EBOV, and mixtures thereof. Thecompounds and compositions of the present invention may also be used incombination with phosphoramidate morpholino oligomers (PMOs), which aresynthetic antisense oligonucleotide analogs designed to interfere withtranslational processes by forming base-pair duplexes with specific RNAsequences. Examples of PMOs include AVI-7287, AVI-7288, AVI-7537,AVI-7539, AVI-6002, and AVI-6003. The compounds and compositions of thepresent invention are also intended for use with general care providedpatients with Filoviridae viral infections, including parenteral fluids(including dextrose saline and Ringer's lactate) and nutrition,antibiotic (including metronidazole and cephalosporin antibiotics, suchas ceftriaxone and cefuroxime) and/or antifungal prophylaxis, fever andpain medication, antiemetic (such as metoclopramide) and/orantidiarrheal agents, vitamin and mineral supplements (including VitaminK and zinc sulfate), anti-inflammatory agents (such as ibuprofen), painmedications, and medications for other common diseases in the patientpopulation, such anti-malarial agents (including artemether andartesunate-lumefantrine combination therapy), typhoid (includingquinolone antibiotics, such as ciprofloxacin, macrolide antibiotics,such as azithromycin, cephalosporin antibiotics, such as ceftriaxone, oraminopenicillins, such as ampicillin), or shigellosis.

In some embodiments a therapeutically effective amount of a compound ofFormula I is formulated as a solution, which may optionally contain atherapeutically effective amount of one or more other compounds usefulfor treating a Filoviridae virus infection. In some embodiments, thesolution can contain another active ingredient for treating aFiloviridae virus infection.

In some embodiments, the additional therapeutic agent used incombination with a compound disclosed herein is active againstFlaviviridae virus infections, particularly Zika virus infections.Non-limiting examples of these other active therapeutic agents areamodiaquine, chloroquine, ribavirin, interferon α, BCX4430, NITD008, andmonoclonal antibodies.

In some embodiments a therapeutically effective amount of a compound ofFormula I is formulated as a solution, which may optionally contain atherapeutically effective amount of one or more other compounds usefulfor treating a Flaviviridae virus infection. In some embodiments, thesolution can contain another active ingredient for treating aFlaviviridae virus infection.

In some embodiments, the additional therapeutic agent used incombination with a compound disclosed herein is active againstParamyxoviridae virus infections, particularly RSV infections.Non-limiting examples of these other active therapeutic agents areribavirin, albuterol, epinephrine, and palivizumab.

In some embodiments a therapeutically effective amount of a compound ofFormula I is formulated as a solution, which may optionally contain atherapeutically effective amount of one or more other compounds usefulfor treating a Paramyxoviridae virus infection. In some embodiments, thesolution can contain another active ingredient for treating aParamyxoviridae virus infection.

In some embodiments, when a compound disclosed herein is combined withone or more additional therapeutic agents as described above, thecomponents of the composition are administered as a simultaneous orsequential regimen. When administered sequentially, the combination maybe administered in two or more administrations.

In some embodiments, a therapeutically effective amount of a compounddisclosed herein is combined with a therapeutically effective amount ofone or more additional therapeutic agents in a unitary dosage form forsimultaneous administration to a patient, for example as a solid dosageform for oral administration.

In some embodiments, a therapeutically effective amount of a compounddisclosed herein is administered with one or more additional therapeuticagents. Co-administration of a therapeutically effective amount of acompound disclosed herein with a therapeutically effective amount of aone or more additional therapeutic agents generally refers tosimultaneous or sequential administration of a compound disclosed hereinand one or more additional therapeutic agents, such that therapeuticallyeffective amounts of the compound disclosed herein and the one or moreadditional therapeutic agents are both present in the body of thepatient.

Co-administration includes administration of unit dosages comprising atherapeutically effective amount of one or more compounds disclosedherein before or after administration of unit dosages of atherapeutically effective amount of one or more additional therapeuticagents, for example, administration of the compound disclosed hereinwithin seconds, minutes, or hours of the administration of one or moreadditional therapeutic agents. For example, in some embodiments, a unitdose of a compound disclosed herein is administered first, followedwithin seconds or minutes by administration of a unit dose of one ormore additional therapeutic agents. Alternatively, in other embodiments,a unit dose of one or more additional therapeutic agents is administeredfirst, followed by administration of a unit dose of a compound disclosedherein within seconds or minutes. In some embodiments, a unit dose of acompound disclosed herein is administered first, followed, after aperiod of hours (e.g., 1-12 hours), by administration of a unit dose ofone or more additional therapeutic agents. In other embodiments, a unitdose of one or more additional therapeutic agents is administered first,followed, after a period of hours (e.g., 1-12 hours), by administrationof a unit dose of a compound disclosed herein.

V. Methods of Treating

In some embodiments, the present invention is directed to methods oftreating a virus selected from the group consisting of Arenaviridae,Coronaviridae, Filoviridae, Flaviviridae, and Paramyxoviridae.

In some embodiments, the present invention is directed to methods oftreating an Arenaviridae virus infection by administering a compound ofFormula I provided herein. In some embodiments, the present invention isdirected to methods of treating an Arenaviridae species infectionsselected from the group of Allpahuayo virus (ALV), Amapari virus (AMAV),Bear Canyon virus (BCNV), Catarina virus, Chapare virus, Cupixi virus(CPXV), Dandenong virus, Flexal virus (FLEV), Guanarito virus (GTOV),Ippy virus (IPPYV), Junin virus (JUNV), Kodoko virus, Lassa virus(LASV), Latino virus (LATV), Lymphocytic choriomeningitis virus (LCMV),Lujo virus, Machupo virus (MACV), Mobala virus (MOBV), Morogoro virus,Mopeia virus (MOPV), Oliveros virus (OLVV), Parana virus (PARV),Pichinde virus (PICV), Pinhal virus, Pirital virus (PIRV), Sabia virus(SABV), Skinner Tank virus, Tacaribe virus (TCRV), Tamiami virus (TAMV),and Whitewater Arroyo virus (WWAV) by administering a compound ofFormula I provided herein. In some embodiments, the present invention isdirected to methods of treating a Lassa virus infection by administeringa compound of Formula I provided herein. In some embodiments, thepresent invention is directed to methods of treating a Junin virusinfection by administering a compound of Formula I provided herein.

In some embodiments, the present invention is directed to methods oftreating a Coronaviridae virus infection by administering a compound ofFormula I provided herein. In some embodiments, the present invention isdirected to methods of treating a Middle East Respiratory Syndrome(MERS) infection by administering a compound of Formula I providedherein. In some embodiments, the present invention is directed tomethods of treating a Severe Acute Respiratory Syndrome (SARS) infectionby administering a compound of Formula I provided herein.

In some embodiments, the present invention is directed to methods oftreating a Filoviridae virus infection by administering a compound ofFormula I provided herein. In some embodiments, the present invention isdirected to methods of treating an ebolavirus infection by administeringa compound of Formula I provided herein. In some embodiments, thepresent invention is directed to methods of treating an ebolavirusinfection selected from the group consisting of: Zaire (i.e. Ebolavirus, EBOV), Sudan, Tai Forest, Bundibugyo, and Reston; byadministering a compound of Formula I provided herein. In someembodiments, the present invention is directed to methods of treating aMarburg virus infection by administering a compound of Formula Iprovided herein.

In some embodiments, the present invention is directed to methods oftreating a Flaviviridae virus infection by administering a compound ofFormula I provided herein. In some embodiments, the present invention isdirected to methods of treating a Zika virus infection by administeringa compound of Formula I provided herein.

In some embodiments, the present invention is directed to a compound ofFormula I provided herein for use in methods of treating an Arenaviridaevirus infection. In some embodiments, the present invention is directedto a compound of Formula I provided herein for use in methods oftreating an Arenaviridae species infections selected from the group ofAllpahuayo virus (ALLV), Amapari virus (AMAV), Bear Canyon virus (BCNV),Catarina virus, Chapare virus, Cupixi virus (CPXV), Dandenong virus,Flexal virus (FLEV), Guanarito virus (GTOV), Ippy virus (IPPYV), Juninvirus (JUNV), Kodoko virus, Lassa virus (LASV), Latino virus (LATV),Lymphocytic choriomeningitis virus (LCMV), Lujo virus, Machupo virus(MACV), Mobala virus (MOBV), Morogoro virus, Mopeia virus (MOPV),Oliveros virus (OLVV), Parana virus (PARV), Pichinde virus (PICV),Pinhal virus, Pirital virus (PIRV), Sabia virus (SABV), Skinner Tankvirus, Tacaribe virus (TCRV), Tamiami virus (TAMV), and WhitewaterArroyo virus (WWAV) by administering a compound of Formula I providedherein. In some embodiments, the present invention is directed to acompound of Formula I provided herein for use in methods of treating aLassa virus infection. In some embodiments, the present invention isdirected to a compound of Formula I provided herein for use in methodsof treating a Junin virus infection.

In some embodiments, the present invention is directed to a compound ofFormula I provided herein for use in methods of treating a Coronaviridaevirus infection. In some embodiments, the present invention is directedto a compound of Formula I provided herein for use in methods oftreating a Middle East Respiratory Syndrome (MERS) infection. In someembodiments, the present invention is directed to a compound of FormulaI provided herein for use in methods of treating an Severe AcuteRespiratory Syndrome (SARS) infection.

In some embodiments, the present invention is directed to a of Formula Iprovided herein for use in methods of treating a Filoviridae virusinfection. In some embodiments, the present invention is directed to aof Formula I provided herein for use in methods of treating anebolavirus infection. In some embodiments, the present invention isdirected to a compound of Formula I provided herein for use in methodsof treating an ebolavirus infection selected from the group consistingof: Zaire (i.e. Ebola virus, EBOV), Sudan, Tai Forest, Bundibugyo, andReston. In some embodiments, the present invention is directed to acompound of Formula I provided herein for use in methods of treating aMarburg virus infection.

In some embodiments, the present invention is directed to a compound ofFormula I provided herein for use in methods of treating a Flaviviridaevirus infection. In some embodiments, the present invention is directedto a compound of Formula I provided herein for use in methods oftreating a Zika virus infection.

In some embodiments, the present invention is directed to the use of acompound of Formula I provided herein in the manufacture of a medicamentfor treating an Arenaviridae virus infection. In some embodiments, thepresent invention is directed to the use of a compound of Formula Iprovided herein in the manufacture of a medicament for treating anArenaviridae species infections selected from the group of: Allpahuayovirus (ALLV), Amapari virus (AMAV), Bear Canyon virus (BCNV), Catarinavirus, Chapare virus, Cupixi virus (CPXV), Dandenong virus, Flexal virus(FLEV), Guanarito virus (GTOV), Ippy virus (IPPYV), Junin virus (JUNV),Kodoko virus, Lassa virus (LASV), Latino virus (LATV), Lymphocyticchoriomeningitis virus (LCMV), Lujo virus, Machupo virus (MACV), Mobalavirus (MOBV), Morogoro virus, Mopeia virus (MOPV), Oliveros virus(OLVV), Parana virus (PARV), Pichinde virus (PICV), Pinhal virus,Pirital virus (PIRV), Sabia virus (SABV), Skinner Tank virus, Tacaribevirus (TCRV), Tamiami virus (TAMV), and Whitewater Arroyo virus (WWAV).In some embodiments, the present invention is directed to the use of acompound of Formula I provided herein in the manufacture of a medicamentfor treating a Lassa virus infection. In some embodiments, the presentinvention is directed to the use of a compound of Formula I providedherein in the manufacture of a medicament for treating a Junin virusinfection.

In some embodiments, the present invention is directed to the use of acompound of Formula I provided herein in the manufacture of a medicamentfor treating a Coronaviridae infection. In some embodiments, the presentinvention is directed to the use of a compound of Formula I providedherein in the manufacture of a medicament for treating a MERS infection.In some embodiments, the present invention is directed to the use of acompound of Formula I provided herein in the manufacture of a medicamentfor treating a SARS infection.

In some embodiments, the present invention is directed to the use of acompound of Formula I provided herein in the manufacture of a medicamentfor treating a Filoviridae virus infection. In some embodiments, thepresent invention is directed to the use of a compound of Formula Iprovided herein in the manufacture of a medicament for treating anebolavirus infection. In some embodiments, the present invention isdirected to the use of a compound of Formula I provided herein in themanufacture of a medicament for treating an ebolavirus infectionselected from the group consisting of: Zaire (i.e. Ebola virus, EBOV),Sudan, Tai Forest, Bundibugyo, and Reston. In some embodiments, thepresent invention is directed to the use of a compound of Formula Iprovided herein in the manufacture of a medicament for treating aMarburg virus infection.

In some embodiments, the present invention is directed to the use of acompound of Formula I provided herein in the manufacture of a medicamentfor treating a Flaviviridae virus infection. In some embodiments, thepresent invention is directed to the use of a compound of Formula Iprovided herein in the manufacture of a medicament for treating a Zikavirus infection.

VI. XRPD Data

In some embodiments, the crystalline forms are characterized by theinterlattice plane intervals determined by an X-ray powder diffractionpattern (XRPD). The diffractogram of XRPD is typically represented by adiagram plotting the intensity of the peaks versus the location of thepeaks, i.e., diffraction angle 20 (two-theta) in degrees. Thecharacteristic peaks of a given XRPD can be selected according to thepeak locations and their relative intensity to conveniently distinguishthis crystalline structure from others.

Those skilled in the art recognize that the measurements of the XRPDpeak locations and/or intensity for a given crystalline form of the samecompound will vary within a margin of error. The values of degree 2θallow appropriate error margins. Typically, the error margins arerepresented by “±”. For example, the degree 20 of about “8.7±0.3”denotes a range from about 8.7+0.3, i.e., about 9.0, to about 8.7-0.3,i.e., about 8.4. Depending on the sample preparation techniques, thecalibration techniques applied to the instruments, human operationalvariation, and etc., those skilled in the art recognize that theappropriate error of margins for a XRPD can be ±0.5; ±0.4; ±0.3; ±0.2;±0.1; ±0.05; or less. In some embodiments of the invention, the XRPDmargin of error is ±0.2. In some embodiments of the invention, the XRPDmargin of error is ±0.5.

Additional details of the methods and equipment used for the XRPDanalysis are described in the Examples section.

The XRPD peaks for crystalline Formula I Form I are shown below in Table1A.

TABLE 1A XRPD peaks for crystalline Formula I Form I Formula I Form IPeak Position [°2θ] Relative Intensity [%] 5.3 100.0 20.6 98.5 17.6 74.816.3 68.1 13.7 67.3 21.0 63.3 22.1 61.8 17.1 61.0 10.7 49.7 14.3 44.021.3 38.0 12.9 32.3 19.2 30.0 25.7 25.4 8.6 25.2 22.7 24.8 25.4 22.824.0 21.3 19.5 17.6 27.0 15.5 20.0 15.1 23.3 14.7 28.7 13.5 29.0 13.432.1 8.1 32.7 8.1 34.8 7.7 11.1 6.5 31.3 5.1 35.7 4.5 30.5 4.0

The XRPD peaks for crystalline Formula I Form II are shown below inTable 1B.

TABLE 1B XRPD peaks for crystalline Formula I Form II Formula I Form IIPeak Position [°2θ] Relative Intensity [%] 22.3 100.0 16.2 66.8 22.526.6 13.8 24.6 12.7 21.1 16.9 19.3 10.6 13.6 14.5 12.2 24.3 11.5 24.010.5 17.6 10.1 23.4 8.3 8.1 7.6 11.0 7.0 26.8 5.9 28.9 5.8 19.6 5.7 27.84.7 26.4 4.3 28.7 4.2 29.8 4.2 33.0 3.7 18.8 3.5 18.3 3.3 32.1 3.1 25.32.8 32.6 2.5 8.6 2.3 34.2 2.1 35.9 2.0 27.2 1.9 28.1 1.8 38.9 1.7 34.61.6 17.1 1.6 35.2 1.6 21.4 1.5 30.6 1.5 25.6 1.3 18.5 1.3 31.7 1.1 36.50.9 37.1 0.4

Calculated powder pattern peaks for crystalline Formula I Form III areshown below in Table 1C.

TABLE 1C Calculated powder pattern peaks for crystalline Formula I FormIII Formula I Form III Peak Position [°2θ] Relative Intensity [%] 4.1100.0 17.1 64.8 8.2 49.2 16.9 30.3 23.8 25.1 14.4 19.7 14.6 18.6 25.615.9 15.2 15.5 25.3 12.0 20.3 11.3 8.4 10.8 19.3 10.7 26.9 10.4 25.7 9.321.7 8.0 24.2 7.8 22.5 6.9 28.1 6.9 20.6 6.7 16.5 6.3 24.4 5.7 21.9 5.121.1 5.0 36.1 4.9 32.2 4.3 9.1 3.9 21.3 3.3 18.4 3.3 28.4 3.0 12.0 2.836.4 2.7 33.4 2.6 28.9 2.6 35.2 2.3 33.2 2.3 31.4 2.2 37.2 2.1 36.9 2.132.1 2.1 24.8 1.9 30.5 1.9 19.0 1.8 33.1 1.8 22.3 1.8 32.6 1.7 27.5 1.731.8 1.5 29.3 1.5 39.2 1.4 25.0 1.4 26.5 1.4 26.1 1.3 29.1 1.3 39.4 1.218.8 1.1 34.6 0.9 29.5 0.8 12.6 0.7 35.7 0.6 34.0 0.6 38.3 0.6 30.2 0.537.7 0.4 23.0 0.3 29.7 0.3 11.5 0.2 5.4 0.1

The XRPD peaks for crystalline Formula I Form IV are shown below inTable 1D.

TABLE 1D XRPD peaks for crystalline Formula I Form IV Formula I Form IVPeak Position [°2θ] Relative Intensity [%] 15.9 100 22.6 20.11 23.9 8.924.3 7.2 19.9 6.91 14.1 6.59 24.9 5.84 16.3 5.7 17.4 5.42 7.9 5.04 32.03.84 12.5 3.12 23.0 2.97 10.6 2.5 16.6 2.5 32.8 2.42 28.3 2.23 26.5 2.1729.1 1.88 14.9 1.61 27.3 1.24 20.8 1.03 11.3 0.97 19.2 0.58 39.2 0.3934.8 0.35 36.0 0.32 30.2 0.3 36.8 0.29 33.8 0.24 31.2 0.16

The XRPD peaks for a mixture of Forms II and Form IV of Formula I(Mixture I) prepared by a process comprising combining Formula I with asolvent, wherein the solvent is isopropyl acetate are shown below inTable 1E.

TABLE 1E XRPD peaks for a mixture of Forms II and Form IV of Formula I(Mixture I) prepared by a process comprising combining Formula I with asolvent, wherein the solvent is isopropyl acetate Mixture I PeakPosition [°2θ] Relative Intensity [%] 12.5 21.8 14.1 30.9 15.9 100.022.6 66.4

The XRPD peaks for a mixture of Forms II and Form IV of Formula I(Mixture II) prepared by a process comprising combining Formula I with asolvent, wherein the solvent is isopropyl acetate are below in Table 1F.

TABLE 1F TABLE 1F: XRPD peaks for a mixture of Forms II and Form IV ofFormula I (Mixture II) prepared by a process comprising combiningFormula I with a solvent, wherein the solvent is isopropyl acetate.Mixture II Peak Position [°2θ] Relative Intensity [%] 16.1 100.0 22.489.3 12.7 33.8 13.9 25.3 24.2 24.1 17.5 21.7 16.8 19.0 11.1 17.3 10.716.8 14.7 14.3 19.8 9.8 8.1 7.6 25.1 6.2 28.8 6.1 26.5 6.1 21.0 5.5 18.95.1 29.9 5.0 32.3 4.3 8.7 3.0 33.3 3.0 34.5 2.9 27.9 1.7 36.2 1.0

The XRPD peaks for a mixture of Forms II and Form IV of Formula I(Mixture III) prepared by a process comprising combining Formula I witha solvent at a temperature, wherein the solvent is isopropyl alcohol andwater and the temperature is 20° C. are below in Table 1G.

TABLE 1G XRPD peaks for a mixture of Forms II and Form IV of Formula I(Mixture III) prepared by a process comprising combining Formula I witha solvent at a temperature, wherein the solvent is isopropyl alcohol andwater and the temperature is 20° C. Mixture III Peak Position [°2θ]Relative Intensity [%] 12.6 28.7 14.1 8.1 16.7 30.8 17.2 13.9 19.6 10.4

The XRPD peaks for crystalline Formula I Maleate Form I are below inTable 1H.

TABLE 1H XRPD peaks for crystalline Formula I Form I Maleate Formula IMaleate Form I Peak Position [°2θ] Relative Intensity [%] 7.3 100.0 9.099.1 17.8 69.0 15.1 67.4 14.7 54.7 22.0 54.6 18.6 53.9 19.1 42.3 25.739.6 6.2 38.8 4.6 37.8 12.4 37.8 20.3 34.4 13.3 32.1 9.9 31.3 16.3 27.323.9 26.5 23.0 23.3 21.1 18.4 11.2 12.8 29.3 12.0 27.4 11.8 28.2 11.031.5 4.7

VII. Preparation of the Crystalline Forms

A. Formula I

One method of synthesizing (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(e.g. a compound of Formula I) has been previously described inco-pending U.S. patent application Ser. No. 14/926,062, and relatedco-pending PCT patent application no. US2015/057933, filed Oct. 29, 2015entitled “METHODS FOR TREATING FILOVIRIDAE VIRUS INFECTIONS.” Thisreference is hereby incorporated herein by reference in its entirety,and specifically with respect to the synthesis of (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate.

For example, in one aspect, provided is a method of producing acomposition comprising one or more crystalline forms of Formula I,wherein the method comprises combining a compound of Formula I with asuitable solvent or a mixture of suitable solvents to produce acomposition comprising one or more crystalline forms of the compound ofFormula I. In another aspect, provided is another method of producing acomposition comprising one or more crystalline forms of Formula I,wherein the method comprises combining Formula I with a suitable solventor a mixture of suitable solvents.

The choice of a particular solvent or combination of solvents or methodof combining solvents affects the formation favoring one crystallineform of Formula I over another. Solvents suitable for crystal formationmay include, for example, water, isopropyl ether, isopropyl acetate,isopropyl alcohol, ethanol, dichloromethane, 2-methyltetrahydrofuran,methyl tert-butyl ether, heptane, acetonitrile, and any mixturesthereof.

The presence of impurities affects the formation favoring onecrystalline form of Formula I over another. In some embodiments, theform is prepared by a process comprising Formula I having impurities. Inanother embodiment, the form is prepared by a process comprisingsubstantially pure Formula I.

In another aspect, provided is also one or more crystalline forms ofFormula I produced according to any of the methods described herein.

It should be understood that the methods for preparing the crystallineforms described herein (including any one or more of crystalline Forms Ito IV and/or Mixtures I, II, and/or III) may yield quantity and qualitydifferences compared to the methods for preparing Formula I produced onlaboratory scale.

Formula I Form I

In some embodiments, provided is a method of producing a compositioncomprising crystalline Form I, wherein the method comprises combiningFormula I with a solvent to produce a composition comprising crystallineFormula I Form I, wherein the solvent is isopropyl ether.

Provided is crystalline Formula I Form I produced by combining Formula Iwith a solvent, wherein the solvent is isopropyl ether.

Formula I Form II

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is ethanol and water.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is ethanol and water.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent at a temperature to produce acomposition comprising crystalline Formula I Form II, wherein thesolvent is isopropyl alcohol and water and the temperature is 50° C.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent at a temperature, wherein the solvent is isopropylalcohol and water and the temperature is 50° C.

In some embodiments, provided is a method of producing crystallineFormula I Form II by contacting Formula I of the invention and a solventmixture of isopropanol and water, wherein Formula I remainssubstantially insoluble in the solvent mixture, under conditionssuitable to prepare cyrstalline Formula I Form II. Formula I used in themethod of the present invention can be crystalline Formula I, such ascrystalline Form I, crystalline Form II, crystalline Form III,crystalline Form IV, or mixtures thereof, such as Mixture I, Mixture IIor Mixture III.

In some embodiments, Formula I can be crystalline Formula I. In someembodiments, Formula I can be a mixture of Formula I Form II and FormulaI Form IV. In some embodiments, Formula I can be Mixture I, Mixture IIor Mixture III. In some embodiments, Formula I can be Mixture II. Insome embodiments, Form II is prepared substantially free of Form IV. Insome embodiments, Formula I includes a mixture of Form II and Form IV,the solvent mixture includes isopropanol and water, wherein Formula Iremains substantially insoluble in the solvent mixture, therebypreparing cyrstalline Form II substantially free of crystalline Form IV.

The isopropanol and water can be present in the solvent mixture in anysuitable ratio where the volume of water is at least as great as thevolume of isopropanol. Representative ratios of the isopropanol andwater include from 1:1 to about 1:5 (V/V), or from 1:1 to about 1:4(V/V), or from 1:1 to about 1:3 (V/V), or from 1:1 to about 1:2 (V/V),or from about 1:1.5 to about 1:2 (V/V). Representative ratios of theisopropanol and water include at least 1:1 (V/V), as well as 1:1.1,1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.5, 1:3,1:4, or 1:5 (V/V). Other ratios of the isopropanol and water include2:2, 2:3, 2:4, 2:5, 2:6, 2:7, 2:8, 2:9, 2:10, 3:3, 3:4, 3:5, 3:6, 3:7,3:8, 3:9 or 3:10 (V/V). In some embodiments, the solvent mixtureincludes isopropanol and water in a ratio of from 1:1 to about 1:2(V/V). In some embodiments, the solvent mixture includes isopropanol andwater in a ratio of from about 2:3 to about 1:2 (V/V). In someembodiments, the solvent mixture includes isopropanol and water in aratio of at least 1:1 (V/V), wherein the water is present in a volumenot less than the volume of isopropanol. In some embodiments, thesolvent mixture includes isopropanol and water in a ratio of about 3:4(V/V). In some embodiments, the solvent mixture includes isopropanol andwater in a ratio of about 3:5 (V/V). In some embodiments, the solventmixture includes isopropanol and water in a ratio of about 1:2 (V/V).

The method of making crystalline Formula I Form II can be performed atany suitable temperature. Representative temperatures for preparation ofcrystalline Formula I Form II about 20° C., or 25, 30, 35, 40, 45, 50,51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 65, 70, 75 or about 80° C.Representative temperatures ranges include 20° C. to 80° C., or 25° C.to 70° C., 30° C. to 60° C., 40° C. to 60° C., 45° C. to 60° C., or 45°C. to 55° C. In some embodiments, the contacting step is performed at atemperature of from about 30° C. to about 60° C. In some embodiments,the contacting step is performed at a temperature of from about 45° C.to about 60° C. In some embodiments, the contacting step is performed ata temperature of about 50° C.

In some embodiments, the contacting step is performed at a temperatureof from about 30° C. to about 60° C. wherein the solvent mixtureincludes isopropanol and water in a ratio of at least 1:1 (V/V), whereinthe water is present in a volume not less than the volume ofisopropanol. In some embodiments, the contacting step is performed at atemperature of from about 45° C. to about 60° C. wherein the solventmixture includes isopropanol and water in a ratio of from 1:1 to about1:3 (V/V). In some embodiments, the contacting step is performed at atemperature of from about 45° C. to about 60° C. wherein the solventmixture includes isopropanol and water in a ratio of from about 2:3 toabout 2:5 (V/V). In some embodiments, the contacting step is performedat a temperature of from about 45° C. to about 60° C. wherein thesolvent mixture includes isopropanol and water in a ratio of about 3:4(V/V). In some embodiments, the contacting step is performed at atemperature of from about 45° C. to about 60° C. wherein the solventmixture includes isopropanol and water in a ratio of about 3:5 (V/V). Insome embodiments, the contacting step is performed at a temperature ofabout 50° C. wherein the solvent mixture includes isopropanol and waterin a ratio of about 1:2 (V/V).

In some embodiments, the crystalline Form II is prepared substantiallyfree of Form IV. In some embodiments, the Mixture II comprises Formula IForm II and Formula I Form IV, such that the crystalline Form II isprepared substantially free of Formula I Form IV.

In some embodiments, provided is a method of producing crystalline FormII, comprising contacting Formula I and a solvent mixture, whereinFormula I comprises Form II and Form IV, wherein the solvent mixturecomprises isopropanol and water in a ratio of about 3:5 (V/V) and is ata temperature of about 50° C., and wherein Formula I remainssubstantially insoluble in the solvent mixture, thereby preparingcyrstalline Form II substantially free of crystalline Form IV.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is 1-propanol.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is 1-propanol.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is tetrahydrofuran.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is tetrahydrofuran.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is 2-propanol.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is 2-propanol.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is acetonitrile.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is acetonitrile.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is dichloromethane.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is dichloromethane.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is ethanol.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is ethanol.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is methyl tert-butylether.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is methyl tert-butyl ether.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is2-methytetrahydrofuran.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is 2-methytetrahydrofuran.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is ethyl acetate andwater.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is ethyl acetate and water.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form II, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form II, wherein the solvent is methyl ethylketone.

Provided is crystalline Formula I Form II produced by combining FormulaI with a solvent, wherein the solvent is methyl ethyl ketone.

Formula I Form III

In some embodiments, provided is a method of producing a compositioncomprising crystalline Form III, wherein the method comprises combiningFormula I with a solvent to produce a composition comprising crystallineForm III, wherein the solvent is dichloromethane.

Provided is crystalline Form III produced by combining Formula I with asolvent, wherein the solvent is dichloromethane.

Formula I Form IV

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form IV, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form IV, wherein the solvent is2-methyltetrahydrofuran and methyl tert-butyl ether.

Provided is crystalline Formula I Form IV produced by combining FormulaI with a solvent, wherein the solvent is 2-methyltetrahydrofuran andmethyl tert-butyl ether.

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Form IV, wherein the method comprisescombining Formula I with a solvent to produce a composition comprisingcrystalline Formula I Form IV, wherein the solvent is2-methyltetrahydrofuran and heptane.

Provided is crystalline Formula I Form IV produced by combining FormulaI with a solvent, wherein the solvent is 2-methyltetrahydrofuran andheptane.

B. Mixtures of Forms of Formula I

In some embodiments, the present invention is directed to a mixture of(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatecrystalline forms (Formula I Mixture).

In some embodiments, the present invention is directed to a mixture of(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm II and (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm IV.

In some embodiments, the present invention is directed to a mixture of(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatecrystalline forms prepared by a process comprising combining Formula Iwith a solvent, wherein the solvent is selected from isopropyl acetateand mixtures of isopropyl alcohol and water. In some embodiments, thepresent invention is directed to a mixture of (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm II and (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm IV prepared by a process comprising combining Formula I with asolvent, wherein the solvent is isopropyl acetate and isopropyl alcohol.In some embodiments, the present invention is directed to a mixture of(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm II and (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm IV prepared by a process comprising combining Formula I with asolvent, wherein the solvent is isopropyl acetate. In some embodiments,the present invention is directed to a mixture of (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm II and (S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoateForm IV prepared by a process comprising combining Formula I with asolvent, wherein the solvent is a mixture of isopropyl alcohol andwater.

Mixtures of Form II and Form IV of Formula I can be prepared by using avariety of solvents or mixtures thereof. Representative solventsinclude, but are not limited to, water, isopropanol (IPA), isoproylacetate (IPAc), tetrahydrofuran (THF), 2-methyltetrahydrofuran (MeTHF),methyl t-butyl ether (MTBE), and combinations thereof. Mixtures of FormII and Form IV can result in Form II and Form IV being present indifferent amounts. Representative mixtures of Form II and Form IVinclude Mixture I, Mixture II and Mixture III, among others.

In some embodiments, provided is a method of producing a mixture of FormII and Form IV, wherein the method comprises combining Formula I with asolvent, wherein the solvent is isopropyl acetate.

Provided is a mixture of Form II and Form IV produced by combiningFormula I with a solvent, wherein the solvent is isopropyl acetate.Provided is a mixture of Form II and Form IV produced by combiningFormula I with a solvent, wherein the solvent is a mixture of isopropylalcohol and water. Provided is a mixture of Form II and Form IV producedby combining Formula I with a solvent, wherein the solvent is a mixtureof 2-methyltetrahydrofuran and methyl t-butyl ether.

When the solvent includes a mixture of solvents, the solvent mixture caninclude a solvent suitable for dissolving the starting material and anantisolvent that is substantially unable to dissolve the startingmaterial. The solvent and antisolvent can be present in any suitableratio. Representative ratios of the solvent and antisolvent include from10:1 to 1:10, or 5:1 to 1:5, 4:1 to 1:4, 3:1 to 1:3, or 2:1 to 1:2(V/V). The ratio of solvent to antisolvent can also change during thecrystallization process, such as by starting at a ratio of solvent toantisolvent of 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1 or 2:1, and thenadding additional antisolvent to change the ratio of solvent toantisolvent to 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10. In someembodiments, the initial ratio of solvent to antisolvent can be about3:1 (V/V), and the final ratio of solvent to antisolvent can be about1:2 (V/V). In some embodiments, the initial ratio of isopropyl alcoholto water can be about 3:1 (V/V), and the final ratio can be about 1:2(V/V). In some embodiments, the initial ratio of solvent to antisolventcan be about 8:1 (V/V), and the final ratio of solvent to antisolventcan be about 1:2 (V/V). In some embodiments, the initial ratio of2-methyltetrahydrofuran (MeTHF) to methyl t-butylether (MTBE) can beabout 8:1 (V/V), and the final ratio can be about 1:2 (V/V).

Mixture I

In some embodiments, provided is a method of producing Mixture I whereinthe method comprises combining Formula I with a solvent, wherein thesolvent is isopropyl acetate.

Provided is Mixture I produced by combining Formula I with a solvent,wherein the solvent is isopropyl acetate.

Mixture II

In some embodiments, provided is a method of producing Mixture II,wherein the method comprises combining Formula I with a solvent, whereinthe solvent is isopropyl acetate.

Provided is Mixture II produced by combining Formula I with a solvent,wherein the solvent is isopropyl acetate.

Mixture III

In some embodiments, provided is a method of producing Mixture III,wherein the method comprises combining Formula I with a solvent at atemperature, wherein the solvent is isopropyl alcohol and water and thetemperature is about 20° C.

Provided is Mixture III produced by combining Formula I with a solventat a temperature, wherein the solvent is isopropyl alcohol and water andthe temperature is about 20° C.

C. Formula I Maleate

In some embodiments, provided is a method of producing a compositioncomprising crystalline Formula I Maleate Form I, wherein the methodcomprises combining Formula I with maleic acid in a solvent to produce acomposition comprising crystalline Formula I Maleate Form I, wherein thesolvent is methanol and isopropyl acetate.

Provided is Formula I Maleate Form I produced by combining Formula Iwith maleic acid in a solvent to produce a composition comprisingcrystalline Formula I Maleate, wherein the solvent is methanol andisopropyl acetate.

VIII. Uses in Manufacturing of Drug Product

Provided are also a use of the crystalline forms described herein in themanufacture of a drug product. The one or more of the compounds ofFormula I described herein may be used as an intermediate in themanufacturing process to produce the drug product.

In some embodiments, a compound of Formula I is used in the manufactureof an active pharmaceutical ingredient. In some embodiments, Formula IForm I is used in the manufacture of an active pharmaceuticalingredient. In some embodiments, Formula I Form II is used in themanufacture of an active pharmaceutical ingredient. In some embodiments,Formula I Form III is used in the manufacture of an activepharmaceutical ingredient. In some embodiments, Formula I Form IV isused in the manufacture of an active pharmaceutical ingredient. In someembodiments, a mixture of forms of Formula I is used in the manufactureof an active pharmaceutical ingredient. In some embodiments, a mixtureof Formula I Form II and Formula I Form IV is used in the manufacture ofan active pharmaceutical ingredient. In some embodiments, Mixture I isused in the manufacture of an active pharmaceutical ingredient. In someembodiments, Mixture II is used in the manufacture of an activepharmaceutical ingredient. In some embodiments, Mixture III is used inthe manufacture of an active pharmaceutical ingredient. In someembodiments, Formula I Maleate Form I is used in the manufacture of anactive pharmaceutical ingredient.

IX. Articles of Manufacture and Kits

Compositions comprising one or more of the compounds of Formula Idescribed herein and formulated in one or more pharmaceuticallyacceptable excipients or other ingredients can be prepared, placed in anappropriate container, and labeled for treatment of an indicatedcondition. Accordingly, there also is contemplated an article ofmanufacture, such as a container comprising a dosage form of one or moreof the compounds of Formula I described herein and a label containinginstructions for use of the compound(s).

In some embodiments, the article of manufacture is a containercomprising a dosage form of one or more of the compounds of Formula Idescribed herein, and one or more pharmaceutically acceptable excipientsor other ingredients. In some embodiments of the articles of manufacturedescribed herein, the dosage form is a solution.

Kits also are contemplated. For example, a kit can comprise a dosageform of a pharmaceutical composition and a package insert containinginstructions for use of the composition in treatment of a medicalcondition. In another embodiment a kit may comprise multiple individualdosage forms, each comprising a therapeutically effective amount of acompound as described herein, and instructions for their administrationto a human in need thereof. Each of the individual dosage forms maycomprise a therapeutically effective amount of a compound as describedherein in combination with at least one pharmaceutically effectiveexcipient. The individual dosage forms may be in the form of, asexamples, a solution, a tablet, a pill, a capsule, a sachet, asublingual medicament, a lyophilized powder, a spray-dried powder, or aliquid composition for oral, parenteral, or topical administration. Theinstructions for use in the kit may be for treating an Arenaviridaevirus infection, a Coronaviridae virus infection, a Filoviridae virusinfection, a Flaviviridae virus infection, or a Paramyxoviridae virusinfection, including the species of each described herein. In someembodiments, the instructions for use in the kit may be for treating aLassa virus infection in a human. In some embodiments, the instructionsfor use in the kit may be for treating a Junin virus infection in ahuman. In some embodiments, the instructions for use in the kit may befor treating a SARS virus infection in a human. In some embodiments, theinstructions for use in the kit may be for treating a MERS virusinfection in a human. In some embodiments, the instructions for use inthe kit may be for treating an ebolavirus infection in a human. In someembodiments, the instructions for use in the kit may be for treating aZika virus infection in a human. In some embodiments, the instructionsfor use in the kit may be for treating an RSV infection in a human. Theinstructions may be directed to any of the viral infections and methodsdescribed herein. The instructions may be for prophylaxis or thetreatment of an existing viral infection.

In some embodiments, the crystalline or salt forms described herein maypotentially exhibit improved properties. For example, In someembodiments, the crystalline or salt forms described herein maypotentially exhibit improved stability. Such improved stability couldhave a potentially beneficial impact on the manufacture of the compoundof Formula I, such as for example offering the ability to store processintermediate for extended periods of time. Improved stability could alsopotentially benefit a composition or pharmaceutical composition of thecompound of Formula I. In some embodiments, the crystalline or saltdescribed herein may also potentially result in improved yield of thecompound of Formula I, or potentially result in an improvement of thequality of the compound of Formula I. In some embodiments, thecrystalline, salt and solvate forms described herein may also exhibitimproved pharmacokinetic properties and/or potentially improvedbioavailability.

X. Methods Example 1. Formula I Form I

Formula I (56.2 mg) was added to a glass vial. Isopropyl ether (about0.5 mL) was added, the vial was capped, and the suspension was stirredat about 21° C. for about 4 days. Formula I Form I was isolated as asolid from the suspension by centrifuge/filtration and characterized asdiscussed below.

Example 2. Formula I Form II

Formula I (0.03 to 0.07 g) was added to a reaction vessel and dosed withabout 0.1 to 0.4 g of ethanol and water mixtures with water activityranging from 0.2 to 0.8. The vessel was sealed and agitated for abouttwo weeks at room temperature. Formula I Form II was isolated andcharacterized as discussed below.

In an alternative method, Formula I (3.7 g) was added to a reactionvessel. Isopropyl alcohol (about 11 mL) and water (about 4 mL) wereadded and the suspension was heated to about 50° C. until dissolutionwas achieved. Water (about 2 mL) was added over about 1 hour at about50° C., and then about 37 mg of Formula I Form II seeds were added.Water (about 6 mL) was added over about 2.5 hours at about 50° C., andthe suspension was stirred at about 50° C. for about 1.5 hours. Water(about 11 mL) was added over about 6 hours, and the suspension wasstirred at about 50° C. for about 9 hours. The suspension was cooled toabout 20° C. over about 6 hours, and the suspension was stirred at about20° C. for about 17 hours. Formula I Form II was isolated as a solidfrom the suspension by filtration and characterized as discussed below.

In an alternative method, crystalline Formula I (7.0 g) was added to areaction vessel. Isopropyl alcohol (about 21 mL) and water (about 35 mL)were added and the suspension was heated to about 50° C. The suspensionwas stirred at about 50° C. for about 18 hours, and was then cooled toabout 20° C. over about 3 hours, and stirred at about 20° C. for about 3hours. Formula I Form II was isolated as a solid from the suspension byfiltration and characterized as discussed below.

Example 3. Formula I Form III

Formula I (41.2 mg) was dissolved in a flask with dichloromethane (97.9mg) at about 21° C. The flask was capped for a few days. Formula I FormIII was observed.

Example 4. Formula I Form IV MeTHF/MTBE

A crude solution of Formula I (8.0 g) in 2-methyltetrahydrofuran (32 mL)was stirred in a reaction vessel at about 20° C., and methyl tert-butylether (4 mL) was added over about 1 hour. Seeds containing a mixture ofForm II and Form IV were added and the suspension was stirred at about20° C. Methyl tert-butyl ether (64 mL) was added over the period ofabout 5 days at about 20° C., and the suspension was stirred at about20° C. for 2 days. Formula I Form IV was isolated as a solid from thesuspension by filtration and dried.

MeTHF/MTBE

(3aR,4R,6R,6aR)-4-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-(hydroxymethyl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxole-4-carbonitrile(10 g, 30 mmol), 2-ethylbutyl((S)-(4-nitrophenoxy)(phenoxy)phosphoryl)-L-alaninate (14 g, 32 mmol),and magnesium chloride (4.4 g, 46 mmol) were added to a reaction vessel.Tetrahydrofuran (about 100 mL) was added, followed by the addition ofN,N-diisopropylethylamine (13 mL, 76 mmol) at about 25° C. After about 3h, the reaction mixture was charged into a pre-cooled (about 10° C.)mixture of methyl tert-butyl ether (about 100 mL) and aqueous citricacid (10 wt %, about 100 mL). The organic and aqueous layers wereseparated, and the organic layer was washed with aqueous potassiumcarbonate (10 wt %, about 150 mL), aqueous potassium carbonate (10 wt %,two times about 100 mL), aqueous ammonium chloride (10 wt %, about 100mL), and aqueous sodium chloride (15 wt %, about 100 mL). The solvent ofthe organic layer was exchanged to acetonitrile and the volume wasadjusted to about 100 mL. The acetonitrile solution was cooled to about0° C. and concentrated hydrochloric acid (about 20 mL) was added. Afterabout 3 h, the reaction mixture was charged into a precooled (about 10°C.) mixture of 2-methyltetrahydrofuran (about 100 mL) and aqueouspotassium bicarbonate (20 wt %, about 100 mL), and rinsed forward with2-methyltetrahydrofuran (about 50 mL). The organic and aqueous layerswere separated, and the organic layer was washed with aqueous potassiumbicarbonate (20 wt %, about 40 mL), and aqueous sodium chloride (15 wt%, about 100 mL). The organic layer was concentrated to about 50 mL, and2-methyltetrahydrofuran (about 50 mL) was charged. The organic layer wasthen washed with aqueous sodium chloride (15 wt %, about 50 mL). Theorganic layer was concentrated and distilled from2-methyltetrahydrofuran until the solution reached a target watercontent of no more than 0.2%. The 2-methyltetrahydrofuran solution(about 200 mL) was polish filtered and a portion (about a third) of the2-methyltetrahydrofuran solution was then concentrated to about 23 mL.Formula I Form IV seeds (about 40 mg) were added at about 20° C., andmethyl tert-butyl ether (about 43 mL) was added over about 8 h. Thesuspension was stirred at about 20° C. for about a week. Formula I FormIV was isolated as a solid from the suspension by filtration andcharacterized as discussed below.

MeTHF/Heptane

In an alternative method,(3aR,4R,6R,6aR)-4-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-(hydroxymethyl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxole-4-carbonitrile(3.0 g, 9.0 mmol), 2-ethylbutyl((S)-(4-nitrophenoxy)(phenoxy)phosphoryl)-L-alaninate (4.3 g, 9.5 mmol),and magnesium chloride (1.3 g, 14 mmol) were added to a reaction vessel.Tetrahydrofuran (about 30 mL) was added, followed by the addition ofN,N-diisopropylethylamine (3.9 mL, 23 mmol) at about 25° C. After about16 h, the reaction mixture was charged into a pre-cooled (about 3° C.)mixture of 2-methyltetrahydrofuran (about 30 mL) and aqueous citric acid(10 wt %, about 30 mL). The organic and aqueous layers were separated,and the organic layer was washed with aqueous potassium carbonate (10 wt%, about 45 mL), aqueous potassium carbonate (10 wt %, two times about30 mL), and aqueous ammonium chloride (10 wt %, about 30 mL). Thesolvent of the organic layer was exchanged to acetonitrile and thevolume was adjusted to about 32 mL. The acetonitrile solution was cooledto about 0° C. and concentrated hydrochloric acid (about 6 mL) wasadded. After about 2 h, the reaction mixture was charged into aprecooled (about 12° C.) mixture of 2-methyltetrahydrofuran (about 30mL) and aqueous potassium bicarbonate (20 wt %, about 30 mL). Theorganic and aqueous layers were separated, and the organic layer waswashed with aqueous potassium bicarbonate (20 wt %, about 12 mL), andaqueous sodium chloride (15 wt %, about 30 mL). The organic layer wasconcentrated to about 12 mL and 2-methyltetrahydrofuran (about 15 mL)was charged. The organic layer was then washed with aqueous sodiumchloride (15 wt %, about 15 mL). The organic layer was concentrated anddistilled from 2-methyltetrahydrofuran until the solution reached atarget water content of no more than 0.2%. The 2-methyltetrahydofuransolution (about 60 mL) was polish filtered and then concentrated toabout 24 mL, and the solution was stirred at about 20° C. Seedscontaining a mixture of Form II and Form IV (about 30 mg) were added,and heptane (about 18 mL) was slowly charged to the suspension. Thesuspension was stirred at about 21° C. for about 1 day, and then afterabout 2 weeks, Formula I Form IV was isolated as a solid from thesuspension by filtration and characterized as discussed below.

Example 5. Mixture I, A Mixture of Form II and Form IV

(3aR,4R,6R,6aR)-4-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-(hydroxymethyl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxole-4-carbonitrile(20 g, 60 mmol), 2-ethylbutyl((S)-(4-nitrophenoxy)(phenoxy)phosphoryl)-L-alaninate (32 g, 72 mmol),and magnesium chloride (8.6 g, 90 mmol) were added to a reaction vessel.Tetrahydrofuran (about 200 mL) was added, followed by the addition ofN,N-diisopropylethylamine (26 mL, 151 mmol) at about 20° C. After about3 h, the reaction mixture was charged into a pre-cooled (about 15° C.)mixture of 2-methyltetrahydrofuran and aqueous citric acid (10 wt %).The organic and aqueous layers were separated, and the organic layer waswashed with aqueous potassium carbonate (10 wt %, about 300 mL), aqueouspotassium carbonate (10 wt %, two times about 200 mL), aqueous ammoniumchloride (10 wt %, about 200 mL), and aqueous sodium chloride (15 wt %,about 200 mL). The solvent of the organic layer was exchanged toacetonitrile and the volume was adjusted to about 200 mL. Theacetonitrile solution was cooled to about 0° C. and concentratedhydrochloric acid (about 40 mL) was added. After about 3 h, the reactionmixture was cooled to about −10° C., charged into a precooled (about 10°C.) mixture of 2-methyltetrahydrofuran (about 200 mL) and aqueouspotassium bicarbonate (20 wt %, about 200 mL). The organic and aqueouslayers were separated, and the organic layer was washed with aqueouspotassium bicarbonate (20 wt %, about 100 mL), and aqueous sodiumchloride (15 wt %, about 200 mL). The organic layer was concentrated toabout 140 mL, and washed with aqueous sodium chloride (15 wt %, about100 mL). The organic layer was concentrated and distilled from2-methyltetrahydrofuran until the solution reached a target watercontent of no more than 0.2%. The 2-methyltetrahydrofuran solution(about 400 mL) was polish filtered and the solvent was exchanged toisopropyl acetate. The isopropyl acetate solution (about 100 mL) wasstirred at about 21° C. Seeds containing a mixture of Form II and FormIV (about 40 mg) were added, and the suspension was stirred at about 21°C. for about 3 days. Crystalline Formula I containing a mixture of FormII and Form IV was isolated as a solid from the suspension by filtrationand characterized as discussed below.

Example 6. Mixture II, A Mixture of Form II and Form IV

(3aR,4R,6R,6aR)-4-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-6-(hydroxymethyl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxole-4-carbonitrile(20 g, 60 mmol), 2-ethylbutyl((S)-(4-nitrophenoxy)(phenoxy)phosphoryl)-L-alaninate (29 g, 63 mmol),and magnesium chloride (8.6 g, 90 mmol) were added to a reaction vessel.Tetrahydrofuran (about 200 mL) was added, followed by the addition ofN,N-diisopropylethylamine (26 mL, 151 mmol) at about 20° C. After about4 h, the reaction mixture was charged into a pre-cooled (about 10° C.)mixture of methyl tert-butyl ether (about 200 mL) and aqueous citricacid (10 wt %, about 200 mL). The organic and aqueous layers wereseparated, and the organic layer was washed with aqueous potassiumcarbonate (10 wt %, about 300 mL), aqueous potassium carbonate (10 wt %,two times about 200 mL), aqueous ammonium chloride (10 wt %, about 200mL), and aqueous sodium chloride (15 wt %, about 200 mL). The solvent ofthe organic layer was exchanged to acetonitrile and the volume wasadjusted to about 200 mL. The acetonitrile solution was cooled to about0° C. and concentrated hydrochloric acid (about 40 mL) was added. Afterabout 3 h, the reaction mixture was cooled to ˜10° C., charged into aprecooled (about 10° C.) mixture of 2-methyltetrahydrofuran (about 200mL) and aqueous potassium bicarbonate (20 wt %, about 200 mL). Theorganic and aqueous layers were separated, and the organic layer waswashed with aqueous potassium bicarbonate (20 wt %, about 80 mL), andaqueous sodium chloride (15 wt %, about 200 mL). The organic layer wasconcentrated to about 100 mL, and washed with aqueous sodium chloride(15 wt %, about 100 mL). The organic layer was concentrated anddistilled from 2-methyltetrahydrofuran until the solution reached atarget water content of no more than 0.2%. The 2-methyltetrahydrofuransolution (about 400 mL) was polish filtered and the solvent wasexchanged to isopropyl acetate. The isopropyl acetate solution (about100 mL) was stirred at about 20° C. Seeds containing a mixture of FormII and Form IV (about 40 mg) were added, and the suspension was stirredat about 20° C. for about 3 days. Crystalline Formula I containing amixture of Form II and Form IV was isolated as a solid from thesuspension by filtration and characterized as discussed below.

Example 7. Mixture III, A Mixture of Form II and Form IV

Formula I (14.0 g) was added to a reaction vessel. Isopropyl alcohol (42mL) and water (14 mL) were added and the suspension was heated to about50° C. until dissolution was achieved. The solution was cooled to about20° C., and about 14 mg of seeds containing a mixture of Form II andForm IV were added. Water (70 mL) was added over about 3 hours at about20° C., and the suspension was stirred at about 20° C. for about 17hours. Crystalline Formula I containing a mixture of Form II and Form IVwas isolated as a solid from the suspension by filtration andcharacterized as discussed below.

Example 8. Formula I Maleate Form I

Dissolved 0.58 g(2S,3R,4R,5R)-2-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-carbonitrilein 5 mL isopropyl acetate (IPAc) in a 20 mL vial with stir bar. Added 4mL IPAc and 0.25 mL ethanol to 150 mg maleic acid in a second vial anddissolved the maleic acid. Added the contents of the second vial to the20 mL vial while stirring. After stirring for about 1 hour, thesuspension was filtered, the filtrant washed with 2.5 mL IPAc, and airdried to isolate(2S,3R,4R,5R)-2-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-carbonitrilemaleate salt.

A mixture of forms of Formula I (3.31 g) and isopropyl acetate (about 20mL) were added to a first reaction vessel, which was capped and stirredmagnetically at high speed. Maleic acid (0.72 g) was added to a secondreaction vessel. Isopropyl acetate (about 20 mL) was added to the secondreaction vessel. Methanol (about 5 mL) was added to the second reactionvessel. Methanol (about 5 mL) was added to the first reaction vessel.The second reaction vessel's contents were added to the first reactionvessel. The first reaction vessel was stirred at about 21° C. for about5 minutes, and then seeded with(2S,3R,4R,5R)-2-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-carbonitrilemaleate salt seeds. The first reaction vessel was capped and stirred atabout 21° C. for about 18 hours. Formula I Maleate Form I was isolatedas a solid from the suspension by centrifuge/filtration andcharacterized as discussed below.

Characterization of the Crystalline Forms

The crystalline forms of the present invention were characterized byvarious analytical techniques, including X-ray powder diffraction(XRPD), differential scanning calorimetry (DSC), thermogravimetricanalysis (TGA), and dynamic vapor sorption (DVS) using the proceduresdescribed below.

X-Ray Powder Diffraction: XRPD analysis was conducted on adiffractometer (PANanalytical XPERT-PRO, PANanalytical B.V., Almelo,Netherlands) using copper radiation (Cu Kα, λ, =1.5418 Å). Samples wereprepared for analysis by depositing the powdered sample in the center ofa steel holder equipped with a zero background plate. The generator wasoperated at a voltage of 45 kV and amperage of 40 mA. Slits used wereSoller 0.02 rad., antiscatter 1.0°, and divergence. The sample rotationspeed was 2 revolutions/second. Scans were performed from 2 to 40° 20during 5 min with a step size of 0.008° 20. Data analysis was performedby X'Pert Date Viewer version 2.2c (PANalytical B.V., Almelo,Netherlands) and X'Pert data viewer version 1.2d (PANalytical B.V.,Almelo, Netherlands).

The XRPD pattern for Formula I Form I is represented in FIG. 1.

The XRPD pattern for Formula I Form II is represented in FIG. 5.

The calculated XRPD pattern for Formula I Form III represented in FIG. 9was calculated by using Mercury 3.1 Development (Build RCS). Singlecrystal data for Formula I Form III was input into Mercury 3.1 tocalculate the XRPD pattern for Formula I Form III.

The XRPD pattern for Formula I Form IV is represented in FIG. 10.

The XRPD pattern for Formula I Mixture I is represented in FIG. 13.

The XRPD pattern for Formula I Mixture II is represented in FIG. 16.

The XRPD pattern for Formula I Mixture III represented in FIG. 19.

The XRPD pattern for Formula I Maleate Form I is represented in FIG. 22.

The XRPD pattern for Formula I Form IV is represented in FIG. 26.

Differential scanning calorimetry: Thermal properties were evaluatedusing a Differential Scanning calorimetry (DSC) instrument (TA Q1000, TAInstruments, New Castle, Del., USA). Approximately 1 to 10 mg of solidsample was placed in a standard aluminum pan vented with a pinhole foreach experiment and heated at a rate of 5 to 10° C./min under a 50mL/min nitrogen purge. Data analysis was conducted using UniversalAnalysis 2000 Version 4.7A (TA Instruments, New Castle, Del., USA).

The DSC for Formula I Form I is represented in FIG. 2.

The DSC for Formula I Form II is represented in FIG. 6.

The DSC for Formula I Form IV is represented in FIG. 11.

The DSC for Formula I Mixture I is represented in FIG. 14.

The DSC for Formula I Mixture II is represented in FIG. 17.

The DSC for Formula I Mixture III is represented in FIG. 20.

The DSC for Formula I Maleate Form I is represented in FIG. 23.

Thermogravimetric analysis: Thermogravimetric analysis (TGA) wasperformed on a TGA instrument (TA Q500, TA Instruments, New Castle,Del., USA). Approximately 1 to 10 mg of solid sample was placed in anopen aluminum pan for each experiment and heated at a rate of 5 to 10°C./min under a 60 mL/min nitrogen purge using. Data analysis wasconducted using Universal Analysis 2000 Version 4.7A (TA Instruments,New Castle, Del., USA).

The TGA for Formula I Form I is represented in FIG. 3.

The TGA for Formula I Form II is represented in FIG. 7.

The TGA for Formula I Form IV is represented in FIG. 12.

The TGA for Formula I Mixture I is represented in FIG. 15.

The TGA for Formula I Mixture II is represented in FIG. 18.

The TGA for Formula I Mixture III is represented in FIG. 21.

The TGA for Formula I Maleate Form I is represented in FIG. 24.

Dynamic vapor sorption: The hygroscopicity was evaluated at roomtemperature using a dynamic vapor sorption (DVS) instrument (TGA Q5000TA Instruments, New Castle, Del.). Water adsorption and desorption werestudied as a function of relative humidity (RH) over the range of 0 to90% at 25° C. The relative humidity in the chamber was increased by 10%RH and held until the solid and atmosphere reached equilibration. Theequilibrium test was continued until passed or expired after 5 or 10hours. At this point, RH was raised 10% higher and the process wasrepeated until 90% RH was reached and equilibrated. During this period,the water sorption was monitored. For desorption, the relative humiditywas decreased in a similar manner to measure a full sorption/desorptioncycle. The cycle was optionally repeated. All experiments were operatedin dm/dt mode (mass variation over time) to determine the equilibrationendpoint. Approximately 5-10 mg of solid was used. Data analysis wasconducted using Universal

Analysis 2000 Version 4.7A (TA Instruments, New Castle, Del., USA).

The DVS for Formula I Form I is represented in FIG. 4.

The DVS for Formula I Form II is represented in FIG. 8.

The DVS for Formula I Maleate Form I is represented in FIG. 25.

The single crystal X-ray diffraction studies were carried out on aBruker APEX II Ultra diffractometer equipped with Mo K_(α) radiation(e.g. Wavelength). Crystals of the subject compound were cut into a0.22×0.18×0.04 mm section and mounted on a Cryoloop with Paratone-N oil.Data were collected in a nitrogen gas stream at a particular temperatureas shown in the Tables below (e.g. 100(2) K or 200(2) K). A total numberof reflections were collected covering the indices, (e.g. −9<=h<=10,−13<=k<=16, −37<=l<=36). Certain reflections were found to be symmetryindependent, with a R_(int) value. Indexing and unit-cell refinementindicated a crystal system (e.g. monoclinic, triclinic, or orthorhombiclattice). The space group, which was uniquely defined by the systematicabsences in the data, was found (e.g. P1, P2(1), C2, and P21212). Thedata were integrated using the Bruker SAINT software program and scaledusing the SADABS software program. Solution by direct methods (SHELXT)produced a complete phasing model compatible with the proposedstructure.

All non-hydrogen atoms were refined anisotropically by full-matrixleast-squares (SHELXL-2014). All hydrogen atoms were placed using ariding model. Their positions were constrained relative to their parentatom using the appropriate HFIX command in SHELXL-2014. Crystallographicdata are summarized in tables below. The absolute stereochemistry wasset to conform to previously studied samples of the same compound.

The single crystal X-ray crystallography data for Formula I Form II issummarized in Table 2A below.

TABLE 2A Single Crystal Data for Formula I Form II Empirical FormulaC₂₇H₃₅N₆O₈P Form and Identification Form II Solvents in StructureIsopropyl Alcohol Acquisition Temperature 100(2) K Space Group P 21 Zvalue 2 Density (Mg/m³) 1.373 Unit Cell Dimensions Distance (Å) Angle(°) a 10.505 α 90 (2) b 12.736 β   100.105 (3) (7) c 11.066 γ 90 (2)

The single crystal X-ray crystallography data for Formula I Form III issummarized in Table 2B below.

TABLE 2B Single Crystal Data for Formula I Form III Empirical FormulaC₂₈H₃₉N₆O₉Cl₂P Form and Identification Form III Solvents in StructureDichloromethane Acquisition Temperature 100(2) K Space Group P 21 Zvalue 2 Density (Mg/m³) 1.348 Unit Cell Dimensions Distance (Å) Angle(°) a 10.5800 α 90 (4) b  7.4526 β    92.500 (4) (3) c 21.5691 γ 90(12) 

The purity profile of various forms of Formula I is summarized in Table3 below,

TABLE 3 Purity Profile Purity Impurity (%) Entry Sample (%) A B C D E FG H 1 Mixture II¹ 97.6 0.36 0.12 0.64 0.79 0.04 0.06 0.27 0.03 2 MixtureI¹ 97.7 0.41 0.08 0.46 0.64 0.10 0.11 0.21 0.04 3 Mixture III² 98.9 0.10ND 0.14 0.50 0.08 0.09 0.14 0.03 4 Form II³ 99.5 0.04 ND 0.06 0.36 0.030.04 0.05 0.02 ¹Prepared using iPAc at 20° C. ²Prepared from Entry 2 bydissolving in IPA/Water (3:1 V/V) at 50° C. followed by addition ofwater (5 V) for a final solvent mixture of IPA/Water (3:6 V/V).³Prepared from Entry 1 in IPA/Water (1:2 V/V) at 50° C. withoutdissolution of solids.wherein Impurity A is(2R,3R,4S,5R)-2-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-carbonitrile:

In some embodiments of the invention, Formula I is hydrated. In someembodiments, ratio of Formula I to water molecules is 1:1.

Solid State NMR: Solid-state NMR (SSNMR) experiments were performed on aBruker Avance I spectrometer (Bruker, Billerica, Mass.) operating at100.51 MHz for ¹³C and 399.66 MHz for ¹H. A Chemagnetics (Ft. Collins,Colo.) Apex probe, refitted with a 7 mm magic angle spinning (MAS)system (Revolution NMR, Ft. Collins, Colo.), was used to acquire thedata. Each sample was packed into a 7 mm zirconia rotor. All experimentswere acquired using cross polarization and magic-angle spinning(CP/MAS). Magic angle spinning speeds were typically 5 kHz. Chemicalshifts are reported relative to TMS via a secondary reference of themethyl peak of 3-methylglutaric acid at 18.84 ppm with an accuracy of±0.2 ppm. Spinning sidebands were eliminated using total sidebandsuppression (TOSS). Saturation recovery was used to measure ¹H T₁relaxation times.

Data collection was done at a nominal temperature of ˜8.5° C.Acquisition parameters included a 1.5 ms cross polarization time, ˜50 msacquisition time, and are cycle delay of ˜2× the ¹H T₁ (˜3.2 seconds).¹H decoupling of ˜64 kHz was used during acquisition. Data was processedin Bruker Topspin 2.1© software package. The free induction decay wasFourier transformed, phased, and baseline corrected.

Solid state NMR for Formula I Form II is represented in FIG. 27.

Solid state NMR for a mixture of Formula I Form II and Form IV (top),Mixture III (middle) and Mixture I (bottom) are represented in FIG. 28.

Solid state NMR for Mixture III (top), a mixture of Formula I Form IIand Form IV (middle), and Mixture II (bottom) are represented in FIG.29.

Competition Experiments

Several experiments were conducted demonstrating the Formula I Form IIis the more stable form.

Formula I was mixed with the corresponding solvent and mixed at roomtemperature via agitator with no stir bar. XRPD of isolated solids wasacquired after two weeks.

Experiment Solvent XRPD 10 Methanol Solution; no XRPD 12 1-propanolPartially converted to Form II 14 THF 16 2-propanol 18 ACN Form II 20DCM Partially converted to Form II 22 Ethanol Form II 24 MTBE Partiallyconverted to Form II 26 2MeTHF 28 EtOAc/water Form II 30 MEK 32Ethanol/water a_(w) 0.4

A competition experiment between Formula I Form I and Formula I Form IIwas conducted by mixing Formula I Form I with isopropyl acetate,followed by adding Mixture II, a mixture of Formula I Form II andFormula I Form IV.

Formula I Formula I Form I Mixture II IPAc Experiment (mg) (mg) (mg)mg/g Comment 26 11 55.4 889 75 Suspension; conversion to Form II in 1day

A competition experiment between Formula I Form II and Formula I Form IVwas conducted by combining Formula I Mixture II with IPA/Water (3/6 V/V)at 50° C. for several days. All experiments showed conversion to FormulaI Form II.

Duration (days Experiment wt % water in suspension) Temp. XRPD DSCComment 023 9.3 1 50 Form II Form II suspension 030 4.9 1; 3 50 Form IIForm II 033 39.5 3 50 Form II Form II weak suspension; strong suspensionafter 3 days 034 49.9 1; 3 50 Form II Form II suspension 037 0.93 2 50,22 NA Form II suspension; Form II at 50 C. and 22 C. (after slow cooland overnight stirring)

Each of the references including all patents, patent applications andpublications cited in the present application is incorporated herein byreference in its entirety, as if each of them is individuallyincorporated. Further, it would be appreciated that, in the aboveteaching of invention, the skilled in the art could make certain changesor modifications to the invention, and these equivalents would still bewithin the scope of the invention defined by the appended claims of theapplication. Each of the references including all patents, patentapplications and publications cited in the present application isincorporated herein by reference in its entirety, as if each of them isindividually incorporated. Further, it would be appreciated that, in theabove teaching of invention, the skilled in the art could make certainchanges or modifications to the invention, and these equivalents wouldstill be within the scope of the invention defined by the appendedclaims of the application.

1. A crystalline form selected from the group consisting of:(S)-2-Ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatecharacterized by an X-ray powder diffraction (XRPD) pattern comprisingdegree 2θ-reflections (±0.2° 2θ) at 5.3°, 20.6°, and 22.7°;(S)-2-Ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatecharacterized by an X-ray powder diffraction (XRPD) pattern comprisingdegree 2θ-reflections (±0.2° 2θ) at 4.1°, 8.2°, 17.1°, and 23.8°;(S)-2-Ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatecharacterized by an X-ray powder diffraction (XRPD) pattern comprisingdegree 2θ-reflections (±0.2° 2θ) at 22.6°, 19.9°, and 14.1°;(S)-2-Ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatecharacterized by an X-ray powder diffraction (XRPD) pattern comprisingdegree 2θ-reflections (±0.2° 2θ) at 15.9°, 22.6°, and 14.1°;(S)-2-Ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatecharacterized by an X-ray powder diffraction (XRPD) pattern comprisingdegree 2θ-reflections (±0.2° 2θ) at 16.1°, 22.4°, and 12.7°;(S)-2-Ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatecharacterized by an X-ray powder diffraction (XRPD) pattern comprisingdegree 2θ-reflections (±0.2° 2θ) at 16.7°, 12.6°, and 17.2°; and(S)-2-Ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoatemaleate characterized by an X-ray powder diffraction (XRPD) patterncomprising degree 2θ-reflections (±0.2° 2θ) at 16.3°, 4.6°, and 9.0°. 2.The crystalline form of claim 1, wherein the crystalline form ischaracterized by an X-ray powder diffraction (XRPD) pattern comprisingdegree 2θ-reflections (±0.2° 2θ) at 5.3°, 20.6°, and 22.7°. 3.(canceled)
 4. The crystalline form of claim 2, wherein the X-ray powderdiffraction (XRPD) pattern further comprises degree 2θ-reflections(±0.2° 2θ) at 17.1° and 20.0°.
 5. The crystalline form of claim 2,characterized by an X-ray powder diffraction (XRPD) patternsubstantially as set forth in FIG.
 1. 6. The crystalline form of claim2, characterized by differential scanning calorimetry (DSC) patternsubstantially as set forth in FIG.
 2. 7. The crystalline form of claim2, characterized by thermogravimetric analysis (TGA) patternsubstantially as set forth in FIG.
 3. 8. The crystalline form of claim2, characterized by a dynamic vapor sorption (DVS) pattern substantiallyas set forth in FIG.
 4. 9.-20. (canceled)
 21. The crystalline form ofclaim 1, wherein the crystalline form is characterized by an X-raypowder diffraction (XRPD) pattern comprising degree 2θ-reflections(±0.2° 2θ) at 4.1°, 8.2°, 17.1°, and 23.8°.
 22. The crystalline form ofclaim 1, wherein the crystalline form is characterized by an X-raypowder diffraction (XRPD) pattern comprising degree 2θ-reflections(±0.2° 2θ) at 22.6°, 19.9°, and 14.1°.
 23. (canceled)
 24. Thecrystalline form of claim 22, wherein the X-ray powder diffraction(XRPD) pattern further comprises degree 2θ-reflections (±0.2° 2θ) 17.4°,7.9° and 12.5°.
 25. The crystalline form of claim 22, characterized byan X-ray powder diffraction (XRPD) pattern substantially as set forth inFIG.
 10. 26. The crystalline form of claim 22, characterized bydifferential scanning calorimetry (DSC) pattern substantially as setforth in FIG.
 11. 27. The crystalline form of claim 22, characterized bythermogravimetric analysis (TGA) pattern substantially as set forth inFIG.
 12. 28. The crystalline form of claim 1 wherein the crystallineform is characterized by an X-ray powder diffraction (XRPD) patterncomprising degree 2θ-reflections (±0.2° 2θ) at 15.9°, 22.6°, and 14.1°.29. (canceled)
 30. The crystalline form of claim 28, wherein the X-raypowder diffraction (XRPD) pattern further comprises degree2θ-reflections (±0.2° 2θ) at 12.5°.
 31. The crystalline form of claim28, characterized by an X-ray powder diffraction (XRPD) patternsubstantially as set forth in FIG.
 13. 32. The crystalline form of claim28, characterized by differential scanning calorimetry (DSC) patternsubstantially as set forth in FIG.
 14. 33. The crystalline form of claim28, characterized by thermogravimetric analysis (TGA) patternsubstantially as set forth in FIG.
 15. 34. The crystalline form of claim1 wherein the crystalline form is characterized by an X-ray powderdiffraction (XRPD) pattern comprising degree 2θ-reflections (±0.2° 2θ)at 16.1°, 22.4°, and 12.7°.
 35. (canceled)
 36. The crystalline form ofclaim 34, wherein the X-ray powder diffraction (XRPD) pattern furthercomprises degree 2θ-reflections (±0.2° 2θ) 13.9°, 24.2°, and 17.5°. 37.The crystalline form of claim 34, characterized by an X-ray powderdiffraction (XRPD) pattern substantially as set forth in FIG.
 16. 38.The crystalline form of claim 34, characterized by differential scanningcalorimetry (DSC) pattern substantially as set forth in FIG.
 17. 39. Thecrystalline form of claim 34, characterized by thermogravimetricanalysis (TGA) pattern substantially as set forth in FIG.
 18. 40. Thecrystalline form of claim 1 wherein the crystalline form ischaracterized by an X-ray powder diffraction (XRPD) pattern comprisingdegree 2θ-reflections (±0.2° 2θ) at 16.7°, 12.6°, and 17.2°. 41.(canceled)
 42. The crystalline form of claim 40, wherein the X-raypowder diffraction (XRPD) pattern further comprises degree2θ-reflections (±0.2° 2θ) at 19.6° and 14.1°.
 43. The crystalline formof claim 40, characterized by an X-ray powder diffraction (XRPD) patternsubstantially as set forth in FIG.
 19. 44. The crystalline form of claim40, characterized by differential scanning calorimetry (DSC) patternsubstantially as set forth in FIG.
 20. 45. The crystalline form of claim40, characterized by thermogravimetric analysis (TGA) patternsubstantially as set forth in FIG.
 21. 46. The crystalline form of claim1, wherein the crystalline form is characterized by an X-ray powderdiffraction (XRPD) pattern comprising degree 2θ-reflections (±0.2° 2θ)at 16.3°, 4.6°, and 9.0°.
 47. (canceled)
 48. The crystalline form ofclaim 46, wherein the X-ray powder diffraction (XRPD) pattern furthercomprises degree 2θ-reflections (±0.2° 2θ) at 6.2° and 7.3°.
 49. Thecrystalline form of claim 46, characterized by an X-ray powderdiffraction (XRPD) pattern substantially as set forth in FIG.
 22. 50.The crystalline form of claim 46, characterized by differential scanningcalorimetry (DSC) pattern substantially as set forth in FIG.
 23. 51. Thecrystalline form of claim 46, characterized by thermogravimetricanalysis (TGA) pattern substantially as set forth in FIG.
 24. 52. Thecrystalline form of claim 46, characterized by a dynamic vapor sorption(DVS) pattern substantially as set forth in FIG.
 25. 53. Apharmaceutical composition comprising a crystalline form of claim 1 anda pharmaceutically acceptable excipient.
 54. The pharmaceuticalcomposition of claim 53, further comprising one to three additionaltherapeutic agents.
 55. The pharmaceutical composition of claim 54,wherein the additional therapeutic agents are each active against avirus selected from the group consisting of Arenaviridae, Coronaviridae,Filoviridae, Flaviviridae, and Paramyxoviridae. 56.-64. (canceled) 65.The pharmaceutical composition of claim 53, wherein the pharmaceuticalcomposition is in a unit dosage form.
 66. The pharmaceutical compositionof claim 65, wherein the unit dosage form is a solution.
 67. Apharmaceutical composition prepared by combining a therapeuticallyeffective amount of a crystalline form of claim 1 with apharmaceutically acceptable excipient.
 68. (canceled)
 69. A method fortreating a virus infection in a human in need thereof, the methodcomprising administering to the human a therapeutically effective amountof a crystalline form of claim
 1. 70. The method for treating a virusinfection in a human of claim 69 wherein the virus infection is causedby a virus selected from the group consisting of Arenaviridae,Coronaviridae, Filoviridae, Flaviviridae, and Paramyxoviridae. 71.(canceled)
 72. A method of preparing a crystalline form of(S)-2-ethylbutyl2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(Formula I) characterized by an X-ray powder diffraction (XRPD) patterncomprising degree 2θ-reflections (±0.2° 2θ) at 22.3°, 16.9°, and 16.2°,comprising Contacting the Formula I and a solvent mixture comprisingisopropanol and water, wherein the Formula I remains substantiallyinsoluble in the solvent mixture, thereby preparing the crystallineform. 73.-83. (canceled)
 84. The crystalline form of claim 21,characterized by a unit cell as determined by single crystal X-raycrystallography of the following dimensions: a=10.5800 (4) Å; b=7.4526(4) Å; c=21.5691 (12) Å; α=90°; β=92.500 (3) °; and γ=90°.